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Aragon DAO Templates Audit

1 Summary

ConsenSys Diligence conducted a security audit on the Aragon 0.8 DAO Templates.

  • Project Name: Aragon dao-templates v0.8
  • Client Name: Aragon
  • Client Contact: Louis Giraux (association@aragon.org), Brett Sun
  • Lead Auditor: Martin Ortner
  • Co-auditors: Sergii Kravchenko
  • Date: 23 Aug 2019
  • Duration: 1 week

2 Audit Scope

This audit covered the following files:

File Name SHA-1 Hash
shared/contracts/BaseTemplate.sol a085e3acea08f4ba74f1f6afbbd00045d011db22
shared/contracts/TokenCache.sol e93cbe72cf6f804e436889f1fa4add21cd5bfe00
templates/bare/contracts/BareTemplate.sol 7f02ee0a1af3e8d9089a71eb782ef9d18e8aa017
templates/company-board/contracts/CompanyBoardTemplate.sol 8af07ce7ff299b48c89fdf165cd8efa45309a82e
templates/company/contracts/CompanyTemplate.sol 6a34bac42ea02ee4abbfdcbf0437e9db0e9a1e9b
templates/membership/contracts/MembershipTemplate.sol eaebf63b173efdbc8252318cbd2a29bebdd15e43
templates/reputation/contracts/ReputationTemplate.sol 9ff127c82c20cb087a66a41eba5c05fb4c8d9668
templates/trust/contracts/MultiSigWallet.sol c2448282059bb320f6ca0fa55f2038b6b22a1a2b
templates/trust/contracts/TrustTemplate.sol 8748bf3bb596433517d373176d57c7e8d1561a53

Client's priority for the agreed duration of the audit (in order):

  • High Priority
    • Company
    • Company-Board
    • Membership
    • Reputation
  • Low Priority (if time permits)
    • Bare
    • Trust

2.1 Out of Scope

  • MulstiSigWallet.sol - was excluded from the audit scope. Nevertheless, the audit team verified that MultiSigWallet.sol is code-identical to the original gnosis MultiSigWallet implementation.
  • TrustTemplate.sol - The Trust DAO template was excluded from scope due to time constraints and complexity of the templates that would not allow a thorough and responsible audit result within the time scheduled.
  • The upgrade to @aragon/apps-agent@2.0.0-rc.1 with aragon/dao-templates#135 is not part of this audit.

The audit team evaluated that the system is secure, resilient, and working according to its specifications. The audit activities can be grouped into the following three broad categories:

  1. Security: Identifying security related issues within the contract.
  2. Architecture: Evaluating the system architecture through the lens of established smart contract best practices.
  3. Code quality: A review of the contract source code. The primary areas of focus include:
    • Correctness
    • Readability
    • Scalability
    • Code complexity

3 System Overview

Aragon provides so-called DAO Template contracts to support the deployment of Aragon organizations. The templates model common organizational structures or DAO scenarios. They aim to provide a way to kickstart an organization and customize it to a client's need. A DAO Template contract deploys a new DAO, installs applications (e.g. those in aragon-apps) required for the DAO scenario, initializes and configures them, and defines the trust relationships between components.

With Aragon 0.8, the following templates are available:

  • Company
  • Company-Board
  • Membership
  • Reputation
  • Trust (not in scope - see Audit Scope)

3.1 Detailed Design

The DAO templates are split into a common part used by many templates which can be found in the ./shared/ folder and implements functionality that caters to all the scenario-specific templates. The BaseTemplate defines constants like the aragonPM name hashes of available applications and provides functionality to deploy a bare DAO, register it on ENS, install applications, and set-up and transfer permissions. TokenCache provides functionality to cache a token across DAO creation transactions. Similar functionality exists to cache multiple tokens, apps or an incomplete DAO set-up where a multi-step deployment is required (company-board and trust templates). Due to the design of the cache, the two-step deployment allows only one DAO to be prepared at a time by a deployer.

The following image provides a high-level components centric view on Aragon applications, their interfaces, the roles they export, and some annotations about who interacts with them.

apps overview

aragonOS

DAO Application and Permission management

A new DAO is deployed by creating a new KernelProxy for the DAO Kernel implementation and setting an initial admin (CREATE_PERMISSIONS_ROLE). The Kernel contains an app mapping, provides functionality to install apps by deploying app proxies, and implements upgradeability for both the kernel and apps. Permissions are managed by the ACL subsystem that controls who has permissions to execute an action in an Aragon application and who can re-grant or revoke that permission (a permission's "manager").

As outlined in the right part of the diagram, the initial admin may grant Kernel.APP_MANAGER_ROLE to an account. This account will be allowed to install/update/manage applications for the DAO. The initial admin may grant or revoke DAO or application specific permissions to an account and specify an account that acts as the permission manager for the specific role.

Exported permissions:

  • Kernel.APP_MANAGER_ROLE
  • ACL.CREATE_PERMISSIONS_ROLE

For reference, ACL provides the following interfaces to manage permissions:

  • Creates a permission that wasn't previously managed.

    function createPermission(address _entity, address _app, bytes32 _role, address _manager)

  • Grants permission if allowed. This requires msg.sender to be the permission manager.

    function grantPermission(address _entity, address _app, bytes32 _role)

  • Grants a permission with parameters if allowed. This requires msg.sender to be the permission manager.

    function grantPermissionP(address _entity, address _app, bytes32 _role, uint256[] _params)

  • Revokes permission if allowed. This requires msg.sender to be the permission manager.

    function revokePermission(address _entity, address _app, bytes32 _role)

  • Set _newManager as the manager of _role in _app. This requires msg.sender to be the permission manager.

    function setPermissionManager(address _newManager, address _app, bytes32 _role)

  • Remove the manager of _role in _app. This requires msg.sender to be the permission manager.

    function removePermissionManager(address _app, bytes32 _role)

  • Burn non-managed _role in _app, so no later modifications can be made (e.g. grant, revoke, permission manager).

    function createBurnedPermission(address _app, bytes32 _role)

  • Burn _role in _app, so no later modification can be made (e.g. grant, revoke, permission manager). This requires msg.sender to be the permission manager.

    function burnPermissionManager(address _app, bytes32 _role)

Applications

The following applications from aragon-apps are provided to organizations through the templates.

Agent

An agent allows performing arbitrary calls to contracts and therefore acts as an external interface of the DAO. It allows the DAO to participate as a stakeholder in other contracts or DAOs. The agent also implements the Vault application (see below). As outlined in the diagram, roles can be assigned to any address.

The EXECUTE_ROLE allows an entity to perform arbitrary calls to contract with ETH value transfer with user provided call-data (execute(target, ethValue, calldata)). The RUN_SCRIPT_ROLE allows an entity to execute an evmScript by calling forward(evmScript), which may call arbitrary addresses depending on the evmscript executor (without ETH value transfer). Both methods allow an entity owning the permission to call addresses within the DAO or external to the DAO on behalf of the Agent.

Exported permissions:

  • Agent.EXECUTE_ROLE
  • Agent.RUN_SCRIPT_ROLE
  • Agent.ADD_PRESIGNED_HASH_ROLE
  • Agent.DESIGNATE_SIGNER_ROLE

With aragon/dao-templates#135 the Agent application will be updated to @aragon/apps-agent@2.0.0-rc.1 providing new functionality and exporting the following additional permissions:

  • Agent.SAFE_EXECUTE_ROLE
  • Agent.ADD_PROTECTED_TOKEN_ROLE
  • Agent.REMOVE_PROTECTED_TOKEN_ROLE

The SAFE_EXECUTE_ROLE allows an entity to execute a low-level call to an arbitrary address with call-data and without a value transfer. The method checks that protected tokens cannot be spent.

Please note that the upgrade to @aragon/apps-agent@2.0.0-rc.1 is not part of this audit.

Finance

The finance application is the central point to keep track of income and expenses (ETH or ERC20 tokens). It can be used to create recurring or one-time payments. Finances are accounted in configurable financial periods (e.g. quarters). A limit on how many units of a token can be spent per period can be defined (budget) with the default being unlimited. If it is set, Finance will only allow the budgeted amount of tokens to be spent for the period. The balance for a period can be negative if it is overspent. The Finance application does not hold funds on its own but interacts with a Vault or Agent application to execute the payment. Financial statements cannot be created manually as they are always based on deposit or spent transactions/events.

An entity allowed to create immediate payments in a system that is not restricted by budgets may be able to spend all of a DAO's funds.

Exported permissions:

  • Finance.CREATE_PAYMENTS_ROLE
  • Finance.CHANGE_PERIOD_ROLE
  • Finance.CHANGE_BUDGETS_ROLE
  • Finance.EXECUTE_PAYMENTS_ROLE
  • Finance.MANAGE_PAYMENTS_ROLE
Voting

Allows the DAO to execute arbitrary actions based on voting results.

An entity may create a vote that executes evmScript when it passes. Stakeholders in the DAO (token holders) can vote with their stake in votings.

Exported permissions:

  • Voting.CREATE_VOTES_ROLE
  • Voting.MODIFY_SUPPORT_ROLE
  • Voting.MODIFY_QUORUM_ROLE
Survey

A survey application similar to Voting for signaling to support and establish community sentiment. It cannot execute any actions.

Token holders may participate in surveys with their stake.

Exported permissions:

  • Survey.CREATE_SURVEYS_ROLE
  • Survey.MODIFY_PARTICIPATION_ROLE
Token Manager

The TokenManager is an abstraction and the controller of a MiniMeToken. A TokenManager for a specific MiniMeToken is set by calling MiniMeToken.changeController(TokenManager). One TokenManager can only be the controller of one MiniMeToken. The TokenManager can mint and destroy tokens, assign them freely, and define token vestings. Token transfers on a controlled MiniMeToken cause a hook to be called on the TokenManager which then decides whether to allow or reject the action.

Token holders of the controlled MiniMeToken may perform actions on behalf of the TokenManager, e.g. to create votes or call arbitrary commands by calling TokenManager.forward(evmScript). If the TokenManager permits, a token holder may freely transfer tokens to other parties.

Exported permissions:

  • TokenManager.MINT_ROLE
  • TokenManager.ISSUE_ROLE
  • TokenManager.ASSIGN_ROLE
  • TokenManager.REVOKE_VESTINGS_ROLE
  • TokenManager.BURN_ROLE
Vault

The value store of the DAO. It manages ERC20 token and ETH assets.

An entity owning the permission to transfer funds has full control over the DAO's assets.

Exported permissions:

  • Vault.TRANSFER_ROLE
Payroll

An application to manage on-chain salary payments that allows employees to see their available balance and request payments.

Exported permissions:

  • Payroll.ADD_EMPLOYEE_ROLE
  • Payroll.TERMINATE_EMPLOYEE_ROLE
  • Payroll.SET_EMPLOYEE_SALARY_ROLE
  • Payroll.ADD_BONUS_ROLE
  • Payroll.ADD_REIMBURSEMENT_ROLE
  • Payroll.ALLOWED_TOKENS_MANAGER_ROLE
  • Payroll.CHANGE_PRICE_FEED_ROLE
  • Payroll.MODIFY_RATE_EXPIRY_ROLE

DAO Templates

The following section describes the DAO Templates in more detail.

Please refer to 5 Security Specification for a discussion about the security properties.

dot file

Inheritance Graph

A complete view of the inheritance structure:

Inheritance graph

Components

An actor-centric view on the DAO Templates indicating what functionality is exposed by the DAO deployment contracts for Bare, Reputation, CompanyBoard, Company, Membership and the Trust template is shown in the following class diagram. Externally reachable methods are annotated in green, internal and private functions are yellow or red. A magnifying glass indicates that the function is pure or view-only. State and constant variables are listed in the top area of the class illustration.

class-uml

Bare Template

The following illustration provides an overview of the high level setup steps for this template.

setup

The Bare template - as the name suggests - deploys a minimum viable DAO. No token will be created by this template. The DAO's name will not be registered with ENS. The template optionally allows to initialize one application of the callers choice and finally transfers permissions to the caller. The application will be initialized with the user provided initializeCalldata. No input validation is or even can be performed on that data. The caller can also provide a list of permissions to create on the application. No input validation is performed on this list as well. Applications that require the presence of a token might not be functional as no token is deployed with the DAO. The DAO's token might pre-exist though. However, any token can be used and it can even be non-conformant to the MiniMeToken implementation generally used.

The result is a minimum viable DAO that is barely functional and requires additional manual effort to be finalized. Please note that there is considerable risk of misconfiguration for this DAO template. The resulting DAO is both non-transparent as the setup is not fully self-contained in a smart-contract and centralized with the deployer being the single point of trust. Even if an application is initially deployed with the template, the application might not be fully functional (e.g. due to dependencies on other applications being installed).

The DAO comes with an unmanaged default EVMScriptRegistry that includes the CallScript executor for use with the forwarding functionality in applications.

This template is meant to be further customized.

Company Template

The following illustration provides an overview of the high level setup steps for this template.

setup

The Company template is similar to the Aragon v0.7 democracy kit with the difference that the Voting.MODIFY_SUPPORT permission is not burned. The company template is based on a token with 18 decimals that is transferable with no limit being set on how many tokens a single account can hold. Token holders with their stakes are the key decision makers.

The template creates the new token according to the token parameters as defined in the contract and deploys a new DAO, initially assigning CREATE_PERMISSIONS and APP_MANAGER roles to itself. Subsequently the DAO apps are installed and initialized, tokens are minted and the apps' permissions are set up. Finally, the CREATE_PERMISSIONS and APP_MANAGER roles are transferred to the Voting application to allow the token holders to vote on DAO related decisions and an ENS name for the DAO is registered.

This template is similar to Reputation and Membership. The main differences are:

  • Reputation does not allow token transfers.
  • Membership defines a fixed stake of one token per member and the token is not transferable.
Reputation Template

The following illustration provides an overview of the high level setup steps for this template:

setup

While the token configuration is different, the permission setup is basically similar to Company. The token is configured to not be transferable.

This template is similar to Company and Membership. The main differences are:

  • Company does allow token transfers.
  • Membership defines a fixed stake of one token per member.
Membership Template

The following illustration provides an overview of the high level setup steps for this template.

setup

The setup is basically similar to Company with the token not being transferable and every member receiving only one token. The TOKEN_MAX_PER_ACCOUNT setting ensures that each token holder's balance cannot exceed one token even after the initial minting during the DAO deployment.

This template is similar to Company and Reputation. The main differences are:

  • Company does allow token transfers.
  • Reputation allows members to have an arbitrary number of tokens.
Company-Board Template

The following illustration provides an overview of the high level setup steps for this template. The deployment is performed in two steps.

setup

This template is based on two major groups of actors. The Board is represented by BOARD token holders, using a membership token (non transferable, one per member) that can be used to vote in the board voting application, and the Shareholders are represented by SHARE token holders, using a token that is transferable with no limit on how many tokens a token holder can possess that can be used to vote in the shareholder voting application.

The DAO is set up by first creating the BOARD and SHARE tokens, then deploying the DAO while initially assigning CREATE_PERMISSIONS and APP_MANAGER roles to the template contract for further configuration. Subsequently the voting applications for BOARD and SHARE are installed and configured. Next, the Vault and Finance applications are installed, initialized, and have their permissions set up accordingly. After this, Payroll is installed and has its permissions set up before finalizing the rest of the permissions on the apps. Finally, the CREATE_PERMISSIONS and APP_MANAGER roles are transferred to the Voting_BOARD application to allow the BOARD to manage DAO related decisions and an ENS name for the DAO is registered.

Shareholders via Voting_SHARE are set to own and manage most permissions in the system.

Board members are granted the following permissions via Voting_BOARD:

  • APP_MANAGER
  • CREATE_PERMISSIONS
  • All relevant payroll permissions (also being permission manager)
  • CREATE_PAYMENTS, MANAGE_PAYMENTS, and EXECUTE_PAYMENTS on Finance
  • EXECUTE calls and RUN_SCRIPT on Agent/Vault

4 Key Observations/Recommendations

  • Basic documentation including raw specifications, descriptions, an overview of the permissions and inline documentation for contracts and their exposed functionality is available.

  • The code is well written and split up into a BaseTemplate with shared functionality intended to be used by the individual DAO manifestations.

  • Company, Membership and Reputation unnecessarily duplicate code leading to minor discrepancies between the code-bases.

  • The Bare template does not deploy a fully configured and therefore usable DAO.

  • Trust assumptions for the Bare template highly depend on how the DAO configuration is finalized.

  • The DAO Templates, similar to aragonOS, uses Solidity version 0.4.24 which is not in the latest major version branch of Solidity.

  • Payroll has no permissions to create payments on Finance. payday() will therefore not be functional.

  • The Survey application is not used by any of the DAO templates.

5 Security Specification

This section describes, from a security perspective, the expected behavior of the system under audit. It is not a substitute for documentation. The purpose of this section is to identify specific security properties and encourage a discussion about security threats to - and trust assumptions of - the system.

The DAO Template contracts can be seen as blue-prints for common DAO scenarios. They initially specify the trust boundaries, actors and functionality provided, the standard applications involved and their configuration as well as the distribution of power that comprises the DAO's intended use case. It is important to note that certain roles in a DAO allow modifications of the DAO after deployment, even when using a DAO template. This is especially true in the beginning of a DAO's life where a smaller group of majority shareholders might have the power to change and decide on core attributes and functionality of the DAO. Deploying a DAO from an audited template is therefore no certification that a DAO is set-up correctly for later users. Furthermore, DAO templates make use of a on-chain repository to retrieve the address of the latest implementation of an application. This information can be updated at any point in time, asynchronous to the release of a new DAO template, given an entity owns the necessary role and permissions to do the repository update. Application implementations are therefore not in scope for this audit.

5.1 DAO Templates

  • The maintainer of a deployed DAO Template may be in control of the application repository that is used with the template and therefore may be able to update application implementations and front-run the DAO deployer, which may result in an unexpected application being deployed.

  • Forwarding functionality in various applications widens the general attack vectors of the system. At this time, no critical attack vectors have been identified.

  • Payroll provides forwarding functionality for Employees that allows them to execute CallScripts by default. The DAO's Finance application is implicitly black-listed by the Payroll application code during forwarding, disallowing Employees from exploiting a potential Payroll <--> Finance trust relationship. Please refer to the Payroll audit for further observations, recommendations and discussions on the trust relationship.

  • Agent allows permission grantees (usually Voting) to run arbitrary CallScripts by default or execute arbitrary calls with an ether value transfer.

  • TokenManagers allow token holders to run arbitrary CallScripts by default. This is usually used to create votes. The managed MiniMeToken is implicitly black-listed by the TokenManager application during forwarding, disallowing token holders from exploiting a direct relationship to the token.

  • Forwarding functionality can generally be exploited to proxy calls to other contracts.

  • An EVMScriptManager permission grantee may add a backdoored or malicious script executor, e.g. to bypass blacklisting restrictions in the default CallScript executor or to execute arbitrary actions.

  • Kernel.APP_MANAGER permission grantee may install, modify or upgrade applications to bypass restrictions or undermine trust assumptions.

  • Voting systems are often the back-bone of the DAOs.

    • In many cases token holders or a special group of DAO members can create votes for benign looking actions that may execute malicious evmscripts in the end. It is therefore paramount for token holders to verify that a vote's action (evmScript) actually reflects the vote's intention and does not perform any malicious activity. Token holders may also attempt to exploit flaws in off-chain applications (e.g. a web application) that are visualizing on-chain stored data like the voting metadata (html injection, presentation layer attacks based on utf8 encoding, ...) to trick stakeholders into voting in their favour.
    • A misconfigured Voting application puts the complete DAO at risk. It is therefore important to re-verify after deployment that the Voting applications are actually configured for the intended quorum and support parameters. Furthermore quorum and support must be chosen wisely for the intended DAO use case.
    • The templates usually allow the token holders to create a vote that attempts to change the application's quorum or support. Any attempt to do so must be carefully reviewed by voters as choosing the wrong parameters for these settings might put the DAO at risk.
    • Majority token holders might overrule other token holders in the system. Token holders might collude or try to buy transferable tokens off exchanges to maximize their decision making power in the DAO with an intent to exploit it.
    • Members might attempt to block the DAOs' decision-making capability by spamming the application with legitimate looking votes. A UI visualization of open votes may easily be overloaded or users might be tricked into participating in the wrong voting if they do not verify that they are participating in the vote they actually want to participate in (i.e. they only check the voting title and not the unique identifier).
  • The DAO templates are initialized with components that may be operated by a 3rd party. When using pre-deployed DAO Template contracts (e.g. deployed by the Aragon Association) the deployer implicitly trusts these entities. For example, the templates are usually initialized with an external DAOFactory, a MiniMeTokenFactory an ENS provider, and a IFIFSResolvingRegistrar. Any of these components may act maliciously, e.g. when bootstrapping a new DAO, creating a new token for the DAO or when resolving the latest version of applications. Users of pre-deployed DAO Template contracts therefore have to make sure that the template has been initialized by an entity they trust.

  • Some templates allow permissions to be delegated to individual entities that are not ruled by a MultiSig contract or Voting application. It should be noted that these entities may have critical permissions within the DAO, for example permissions that can indirectly cause harm to the DAO, e.g. by transferring funds from the Vault (PayrollManager -> Payroll -> Finance -> Vault -> transfer salary, PriceFeed -> unfair exchange rate for employee or DAO -> transfer funds). It is recommended to avoid assigning potentially harmful permissions to individuals as there is a possibility that they turn rogue or are taken over by a third-party to exploit the DAO. Safeguards must be implemented in order to avoid being exploited by third party oracles.

    • Individual permission owners should prove that they took proper action and implemented secure procedures for key management of their accounts.
  • Some of the DAOs generated by the templates under audit make use of what are described as "non-transferable tokens" or "memberships". In the current implementation, nothing prevents the control of such memberships being transferred or traded if they are under the control of a proxy contract.

    • For example, if membership is granted to an address X that has never sent a transaction, then nothing prevents the subsequent creation of a BoardMember is Ownable contract at address X. If BoardMember were to expose a vote(...) public onlyOwner function that proxies votes through to the DAO, then the supposedly non-transferable membership is under the control of the BoardMember's current owner, and that ownership can be freely reassigned. Membership can therefore be transferred or even traded.

    • Depending on the social-layer processes around membership allocation, this sort of theoretical transferability might be moot (e.g. if all member addresses must have originated past transactions and are therefore known to be non-contracts).

    • If no such social-layer defense can be assumed to exist, then we note that the non-transferability property of memberships will not be guaranteed.

    • Ultimately membership association is always susceptible to vectors that are socially impossible to prevent, like transferring or sharing of private keys.

  • The DAO templates do not remain in direct control of the deployed DAOs and transfer ownership and all permissions of the DAO to either an individual or the DAO itself.

The following sections describes each specific template's security in more detail.

Bare Template

setup

This template is meant to provide a minimum viable DAO that should be further customized by the organization. Not only for transparency it is recommended to create individual deployment templates for the type of DAO that is needed by a client. DAO templates are highly critical as they are the blueprint for the organization and any misconfiguration can lead to loss of funds or an inability to control the DAO. For production use, a unit-tested deployment contract should be created.

Actors

The relevant actors are as follows:

  • Template maintainer - deploys and configures the template contract. Is in control of factories used to deploy a new DAO.
  • deployer - interacts with the Bare template to deploy a new DAO.
  • authorizedAddress - an address that is being granted specific permissions on an application.
Trust Model
  • Template maintainer is a trusted entity.

  • The trust model is very broad as the deployer might install arbitrary apps with this template.

  • the DAO template does not remain in control of the newly deployed DAO.

  • The deployer is in full control of every aspect of the DAO.

  • The deployer remains in full control of the DAO even after it has been deployed.

  • The deployer can create, grant and revoke any permission (CREATE_PERMISSIONS_ROLE, permission manager for application permissions).

  • The deployer is the designated manager of the DAO's applications (APP_MANAGER) and can therefore install or upgrade applications at any time.

  • The authorizedAddress is an account designated by the deployer that is granted deployer-specified permissions on an application that is initially created and linked to the DAO.

  • This setup is highly centralized with all power being in the hands of the deployer.

  • This setup is not meant to be used as-is in production but rather as a starting point to build a custom DAO.

  • The template provides the ability to install and initialize one application with the DAO. This functionality is very limited, might not be useful for all applications and therefore leave them in a semi-configured state. The original rationale for providing the "first" application is to make it a little bit easier to use the organization (e.g. a single-app organization, which would work for an organization with just a vault).

  • Individual accounts are used. The risk of accidental or forceful loss of control of the actors account(s) must be considered.

  • It is not recommended to base any production DAO on this template.

Company Template

setup

The central trust anchor for this DAO template is the token holder voting application. The DAO's token is transferable and the amount of stake an individual address can have is unlimited. Tokens may also be transferred and traded on exchanges.

Actors

The relevant actors are as follows:

  • Template maintainer - deploys and configures the template contract. Is in control of factories used to deploy a new DAO.
  • deployer - interacts with the Company template to deploy a new DAO.
  • TokenHolder - are the main decision makers in the DAO. They can create and cast votes to perform actions with the DAO.
  • Employee - is an account set-up for payroll in the Payroll application.
  • EmployeeManagerOrVoting - is either the DAO's stakeholders represented by the voting application or a designated account in charge of managing employees and their salary.
  • PriceFeedProvider - Payroll price feed provider
Trust Model

In any smart contract system, it's important to identify what trust is expected/required between various actors. For this audit, we established the following trust model:

  • Template maintainer is a trusted entity.

  • The deployer initially deploys the DAO and transfers all permissions to the Voting application.

  • Employees can call arbitrary addresses via Payroll.forward(evmscript) (Finance is blacklisted).

  • TokenHolder can call arbitrary addresses via TokenManager.forward(evmscript) (e.g. in a malicious way in an attempt to cover their tracks when interacting with a third party contract).

  • TokenHolder can create an arbitrary number of votes via TokenManager.forward(evmscript) due to TokenManager's permission on Voting to Voting.CREATE_VOTE.

  • TokenHolder might create a benign looking vote with a malicious script that is being executed when the vote passes.

  • TokenHolder's can freely transfer, buy and sell tokens. They can collude and cast votes that they benefit from.

  • EmployeeManagerOrVoting can drain funds from the Vault if Payroll would be set up correctly with Finance to execute immediate payments by adding an address as an employee, setting a salary that is high enough but still in the Finance period's budget (with enough funds in the vault) and having the employee interact with Payroll to pay out the salary.

  • Employee may use Payroll's forwarding functionality to proxy calls to arbitrary accounts in an attempt to hide potentially malicious activity.

  • The "company" is run by TokenHolders via a central voting application.

    • Key properties of the decision making process are the voting application's support and quorum settings. These settings must be aligned with the DAO's audience and number of TokenHolders. A combination of quorum and support that is set too low may leave the DAO vulnerable to minority shareholders, whereas setting support or quorum too high may render the DAO uncontrollable with votes being unable to pass (DoS).
    • Majority TokenHolders might decide to abstain from voting to intentionally boycott votes due to required quorum not being reached (DoS).
    • Especially in the beginning of the DAO, there may be increased risk of single entities becoming majority TokenHolders who might attempt to create and execute votes to exploit the DAO.
    • There is a risk of dead-stake where TokenHolder hold tokens but abstain from voting.
  • Both Employees and the DAO have to trust the PriceFeedProvider to receive fair exchange rates.

  • If Agent is used as the DAO's Vault, TokenHolders might decide to pass a vote that calls Agent.execute and transfer funds from the Vault bypassing the Finance application's budgeting.

  • Payroll currently has no permissions on Finance to create payments. Employees therefore cannot call payday to receive their salary. It is important to make sure that Employees are not allowed to call Finance via Payroll.forward(evmscript) or else Payroll might be bypassed and funds might be lost.

Reputation Template

setup

This template shares its security properties and actors with the Company template. The main difference is that tokens are not transferable and represent each member's reputation in the DAO. Token amount per address is not limited. Any member can create votes in the DAO.

Membership Template

setup

This template shares its security properties and actors with the Company template. A main difference is that tokens are not transferable and DAO token holders are limited to one token per address. Every member's voice has the same weight in the voting application and any member can create votes.

Company-Board Template

setup

This DAO template is based on split responsibilities where a Board steers the company and is allowed to perform certain DAO-related actions on their own (through Board-approved voting decisions) without having to ask shareholders. The shareholders are the controlling party for most actions but are purely reactionary to the Board as only the Board members are allowed to create new shareholder votes.

Board tokens are basically membership tokens where every board member is limited to one token that is not transferable. Share token holders can hold any amount of tokens, freely transfer and exchange them similar to the Company template.

Actors

The relevant actors are as follows:

  • Template maintainer - deploys and configures the template contract. Is in control of factories used to deploy a new DAO.
  • deployer - interacts with the company template to deploy a new DAO.
  • Boardmember - individual members holding Board tokens.
  • BOARD - Boardmember's voting application that steers the company.
  • Shareholder - are the controlling party for most actions. They cannot initiate changes and completely rely on Boardmembers to suggest changes.
  • Employee - is an account set-up for payroll in the Payroll application.
  • EmployeeManagerOrBoardVoting - is either the DAO's boardmembers represented by their voting application or a designated account in charge of managing employees and their salary.
  • PriceFeedProvider - Payroll price feed provider.
Trust Model

In any smart contract system, it's important to identify what trust is expected/required between various actors. For this audit, we established the following trust model:

  • Template maintainer is a trusted entity.

  • The deployer initially deploys the DAO and transfers APP_MANAGEMENT and CREATE_PERMISSION permissions to the BOARD voting application.

    • Having APP_MANAGEMENT permissions that are only governed by the board while all other permissions are under control of shareholders might allow a malicious BOARD to update applications in order to completely bypass shareholders and take over the DAO.
    • CREATE_PERMISSON allows a malicious BOARD to take ownership of unassigned and unburned permissions and potentially elevate their privileges, bypassing shareholder control to take over the DAO. Please refer to the diagram for a list of un-assigned permissions.
  • Boardmembers are in charge of configuring the Payroll application. Board members can transfer Payroll permissions without control from shareholders.

  • Boardmembers define EmployeeManagerOrBoardVoting.

  • EmployeeManagerOrBoardVoting can drain funds from the Vault if Payroll would be set up correctly with Finance to execute immediate payments by adding an address as an employee, setting a salary that is high enough but still in the Finance periods budget (with enough funds in the vault) and having the employee interact with Payroll to pay out the salary.

  • Employees can call arbitrary addresses via Payroll.forward(evmscript) (Finance is blacklisted)

  • Employee may use Payrolls forwarding functionality to proxy calls to arbitrary accounts in an attempt to hide potentially malicious activity.

  • Both Employees and the DAO have to trust the PriceFeedProvider to receive fair exchange rates.

  • Payroll currently has no permissions on Finance to create payments. Employees therefore cannot call payday to receive their salary. It is important to make sure that Employees are not allowed to call Finance via Payroll.forward(evmscript) or otherwise Payroll might be bypassed and funds might be lost.

  • Each Boardmember's voice has the same weight in votes.

  • Boardmembers can call arbitrary addresses via TokenManager_BOARD.forward(evmscript) (e.g. in a malicious way in an attempt to cover their tracks when interacting with a third party contract).

  • Boardmembers can create votes on the BOARD's voting application.

  • Boardmembers can create votes on the Shareholder's voting application.

  • Boardmembers may also be a Shareholder in the DAO and therefore also have a stake in votes they propose to Shareholders.

  • Boardmembers may create a benign looking votes with a malicious script that is being executed when the vote passes (to trick other Boardmembers or Shareholders).

  • Boardmembers may propose to Shareholders the addition of an unsafe EVMScriptExecutor that allows them to bypass Shareholders.

  • Boardmembers may drain funds from the Vault bypassing Finance by interacting with Agent.forward or Agent.execute.

  • Shareholders cannot intervene if every Boardmember is malicious as only a Boardmember can propose changes.

  • Shareholders control BOARD membership by minting or burning tokens to accounts. However, their control is passive and can only be executed if a Boardmember proposes the addition or eviction of new BOARD members.

  • Shareholders can call arbitrary addresses via TokenManager_Share.forward(evmscript) (e.g. in a malicious way in an attempt to cover their tracks when interacting with a third party contract).

  • Shareholders can freely transfer, buy and sell tokens to increase their stake.

  • Shareholders cannot initiate votes.

  • The "company" is run by Boardmembers via a central voting application.

    • Key properties of the decision making process are the voting applications' support and quorum settings. These settings must be aligned with the DAO's audience and number of Boardmembers. A combination of quorum and support that is set too low may leave the DAO vulnerable to minority Shareholders and on the other hand setting support or quorum too high may render the DAO uncontrollable with votes being unable to pass (DoS).
    • There is a risk of dead-stake where Boardmembers hold tokens but abstain from votes.

Trust Template

Excluded from audit scope - see Audit Scope)

6 Issues

Each issue has an assigned severity:

  • Minor issues are subjective in nature. They are typically suggestions around best practices or readability. Code maintainers should use their own judgment as to whether to address such issues.
  • Medium issues are objective in nature but are not security vulnerabilities. These should be addressed unless there is a clear reason not to.
  • Major issues are security vulnerabilities that may not be directly exploitable or may require certain conditions in order to be exploited. All major issues should be addressed.
  • Critical issues are directly exploitable security vulnerabilities that need to be fixed.

The following table contains all the issues discovered during the audit, ordered based on their severity.

Chapter Issue Title Issue Status Severity
6.1 Company-Board - Kernel.APP_MANAGER permission should be ruled by Shareholders instead of Board members Closed Major
6.2 Inconsistent Permission Specification DISABLE_PAYMENTS Closed Major
6.3 Company-Board - Inconsistent permissions in Agent application Closed Medium
6.4 Company-Board - Inconsistent permissions in Finance application Closed Medium
6.5 Payroll is missing permissions to create payments on Finance Closed Medium
6.6 Reputation - Missing data location for argument Closed Minor
6.7 Specification Inconsistencies Closed Minor
6.8 Input Validation - aragonId should be checked for empty string Closed Minor
6.9 Company, Reputation, Membership - Code Duplications Deferred Minor

6.1 Company-Board - Kernel.APP_MANAGER permission should be ruled by Shareholders instead of Board members

Severity Status Remediation Comment
Major Closed Fixed by implementing the recommended remediation with https://github.com/aragon/dao-templates/pull/150.

Description

The Company-Board template consists of two groups of decision makers, the BOARD members represented by the board Voting application and the SHARE token holders represented by the SHARE Voting application. BOARD members are the only group allowed to create votings on the SHARE and BOARD Voting applications. SHARE holders hold all of the permissions management roles in the DAO except for permissions in Payroll.

When a new Company-Board based DAO is deployed, core DAO permissions like Kernel.APP_MANAGER and Acl.CREATE_PERMISSIONS are assigned to the BOARD Voting application with the permission manager being set to the SHARE Voting application.

code/templates/company-board/contracts/CompanyBoardTemplate.sol:L100-L100

_transferRootPermissionsFromTemplateAndFinalizeDAO(dao, boardVoting, shareVoting);

The Kernel.APP_MANAGER permissions allow the grantee to install new applications or upgrade existing ones. The board might use the upgrading functionality to upgrade existing applications and therefore work around limitations where the board would actually require a passing vote from the shareholders.

Remediation

Kernel.APP_MANAGER should be assigned to Voting_SHARE to force boardmembers to go through a vote in Voting_SHARE when managing applications. The assumption is that this allows shareholders to block potentially malicious behavior when the board tries to undermine the shareholder trust relationship.


6.2 Inconsistent Permission Specification DISABLE_PAYMENTS

Severity Status Remediation Comment
Major Closed Fixed by replacing DISABLE_PAYMENTS with MANAGE_PAYMENTS in the documentation with https://github.com/aragon/dao-templates/pull/150. The code itself already assigned MANAGE_PAYMENTS permissions.

Description

The specification for template Company,Company-Board, Reputation, Membership and trust lists a permission Finance.DISABLE_PAYMENTS that does not exist. The permission Finance.MANAGE_PAYMENTS which is not listed in the specification is assigned to Voting instead.

code/templates/trust/README.md:L87-L87

| Finance               | DISABLE_PAYMENTS      | Hold Voting         | Hold Voting        |

code/templates/reputation/README.md:L61-L61

| Finance           | DISABLE_PAYMENTS      | Voting        | Voting  |

code/templates/membership/README.md:L60-L60

| Finance           | DISABLE_PAYMENTS      | Voting        | Voting  |

code/templates/company/README.md:L61-L61

| Finance           | DISABLE_PAYMENTS      | Voting        | Voting  |

code/templates/company-board/README.md:L67-L67

| Finance             | DISABLE_PAYMENTS      | Share Voting        | Share Voting  |

Remediation

The specification should always reflect the trust model the DAO template is configuring. It is therefore important to make sure the specification is accurate at all times. Correct the specification to include Finance.MANAGE_PAYMENTS instead of Finance.DISABLE_PAYMENTS.


6.3 Company-Board - Inconsistent permissions in Agent application

Severity Status Remediation Comment
Medium Closed Fixed by removing Shareholder EXECUTE and RUN_SCRIPT roles on Agent with https://github.com/aragon/dao-templates/pull/150. With this change only Board owns EXECUTE and RUN_SCRIPT permissions, managed by Shareholder.

Description

Shareholders have EXECUTE_ROLE and RUN_SCRIPT_ROLE roles in the Agent application of a DAO created from the Company-Board template.

code/templates/company-board/contracts/CompanyBoardTemplate.sol:L203-L210

function _createCustomAgentPermissions(ACL _acl, Agent _agent, Voting _shareVoting, Voting _boardVoting) internal {
    address[] memory grantees = new address[](2);
    grantees[0] = address(_shareVoting);
    grantees[1] = address(_boardVoting);

    _createPermissions(_acl, grantees, _agent, _agent.EXECUTE_ROLE(), _shareVoting);
    _createPermissions(_acl, grantees, _agent, _agent.RUN_SCRIPT_ROLE(), _shareVoting);
}

Company-Board DAO should have all the executive roles assigned to the board only and shareholders should be able to change the board or do the major changes to the system.

Remediation

Remove EXECUTE_ROLE and RUN_SCRIPT_ROLE roles in Agent app from the shareholders (while preserving shareholders as the role managers).


6.4 Company-Board - Inconsistent permissions in Finance application

Severity Status Remediation Comment
Medium Closed Fixed by removing Shareholder permissions on Finance with https://github.com/aragon/dao-templates/pull/150. With this change only Board is in control of Finance permissions (CREATE_PAYMENTS,EXECUTE_PAYMENTS, MANAGE_PAYMENTS) while Shareholder manage the permissions.

Description

Current permission setup for the Finance application in Company-Board template has some inconsistency.

code/templates/company-board/contracts/CompanyBoardTemplate.sol:L212-L220

function _createCustomFinancePermissions(ACL _acl, Finance _finance, Voting _shareVoting, Voting _boardVoting) internal {
    address[] memory grantees = new address[](2);
    grantees[0] = address(_shareVoting);
    grantees[1] = address(_boardVoting);

    _createPermissions(_acl, grantees, _finance, _finance.CREATE_PAYMENTS_ROLE(), _shareVoting);
    _acl.createPermission(_shareVoting, _finance, _finance.EXECUTE_PAYMENTS_ROLE(), _shareVoting);
    _acl.createPermission(_shareVoting, _finance, _finance.MANAGE_PAYMENTS_ROLE(), _shareVoting);
}

Board members are allowed to schedule payments and make immediate payments, which gives the board full control over the funds (they can create immediate payments to drain the Vault). Because of that, board members should also be able to execute their scheduled payments and cancel them.

Additionally, shareholders are able to create, manage and execute payments which are the executive roles and should only be granted to the board.

Remediation

Let the board have the CREATE_PAYMENTS_ROLE, EXECUTE_PAYMENTS_ROLE and MANAGE_PAYMENTS_ROLE roles in the Finance app and remove these roles from the shareholders (while preserving shareholders as the role managers).


6.5 Payroll is missing permissions to create payments on Finance

Severity Status Remediation Comment
Medium Closed Fixed by implementing the recommended remediation with https://github.com/aragon/dao-templates/pull/150. Permission assignment is broken up into multiple steps: the Finance app setup creating EXECUTE and MANAGE payment roles, another method creating the CREATE_PAYMENTS role - for some contracts - with permission manager initially set to the template contract (all but Bare and Trust template), subsequently granting CREATE_PAYMENTS to Payroll and finally transferring the role permission manager from the template to the DAO scenario specific role manager. The template contract does not remain any permissions on Finance for the deployed DAO. https://github.com/aragon/dao-templates/pull/150 introduced an inconsistency with the documentation that has been addressed with https://github.com/aragon/dao-templates/pull/153.

Description

Employees will not be able to get their salary as Payroll does not have permissions on Finance to create payments. This permission is needed in order to pay out employee salaries when an employee calls Payroll.payday().

Remediation

Grant CREATE_PAYMENT permission on Finance for Payroll. Note even though Payroll allows employees to call evmScripts, interaction with Finance via forward() is blacklisted.


6.6 Reputation - Missing data location for argument

Severity Status Remediation Comment
Minor Closed Fixed by adding the missing data location with https://github.com/aragon/dao-templates/pull/150.

Description

Data location declaration is inconsistent within code that has been duplicated for templates that are very similar (e.g. Company, Reputation).

code/templates/reputation/contracts/ReputationTemplate.sol:L128-L128

uint64[3] _votingSettings,

Remediation

Specify the data location for the array: uint64[3] memory _votingSettings


6.7 Specification Inconsistencies

Severity Status Remediation Comment
Minor Closed Fixed with https://github.com/aragon/dao-templates/pull/150.

Description

  • name in spec is id in code

code/templates/company/README.md:L22-L27

- `name`: Name for org, will assign `[name].aragonid.eth`
- `holders`: Array of token holder addresses
- `stakes`: Array of token stakes for holders (token has 18 decimals, multiply token amount `* 10^18`)
- `votingSettings`: Array of [supportRequired, minAcceptanceQuorum, voteDuration] to set up the voting app of the organization
- `financePeriod`: Initial duration for accounting periods, it can be set to zero in order to use the default of 30 days.
- `useAgentAsVault`: Use an Agent app as a more advanced form of Vault app

code/templates/company/contracts/CompanyTemplate.sol:L74-L81

function newInstance(
    string memory _id,
    address[] memory _holders,
    uint256[] memory _stakes,
    uint64[3] memory _votingSettings,
    uint64 _financePeriod,
    bool _useAgentAsVault
)

Same discrepancy for company-board, membership, reputation, trust.

Remediation

Make sure the code is reflecting the specification.


6.8 Input Validation - aragonId should be checked for empty string

Severity Status Remediation Comment
Minor Closed Fixed by adding the length check for id and negative tests to the test-suite with https://github.com/aragon/dao-templates/pull/150.

Description

Upon creating a new instance in all but the Bare template, the caller provides an id argument to be registered for the org as an ENS subdomain in the form of [id].aragonid.eth. An empty string for id should not be allowed for registration and therefore checked before trying to register the ENS subdomain.

code/templates/company/contracts/CompanyTemplate.sol:L74-L90

function newInstance(
    string memory _id,
    address[] memory _holders,
    uint256[] memory _stakes,
    uint64[3] memory _votingSettings,
    uint64 _financePeriod,
    bool _useAgentAsVault
)
    public
{
    _ensureCompanySettings(_holders, _stakes, _votingSettings);

    (Kernel dao, ACL acl) = _createDAO();
    (, Voting voting) = _setupApps(dao, acl, _holders, _stakes, _votingSettings, _financePeriod, _useAgentAsVault);
    _transferRootPermissionsFromTemplateAndFinalizeDAO(dao, voting);
    _registerID(_id, dao);
}

code/shared/contracts/BaseTemplate.sol:L322-L325

function _registerID(string memory _name, address _owner) internal {
    require(address(aragonID) != address(0), ERROR_ARAGON_ID_NOT_PROVIDED);
    aragonID.register(keccak256(abi.encodePacked(_name)), _owner);
}

An attempt to register an empty subdomain will subsequently fail in FIFSResolvingRegistrar of the aragon-id codebase because this will essentially try to register the name of the rootNode. However, it will fail only late in the DAO deployment process but should do so earlier. It will also be more consistent with the input validation checks that are already in place.

contracts/FIFSResolvingRegistrar.sol:L54-L57

function registerWithResolver(bytes32 _subnode, address _owner, IPublicResolver _resolver) public {
    bytes32 node = keccak256(rootNode, _subnode);
    address currentOwner = ens.owner(node);
    require(currentOwner == address(0));

Remediation

Make sure a valid id was provided, e.g. by adding the following check: require(bytes(id).length > 0, ID_FOR_DAO_REQUIRED).

We suggest to implement the same check in FIFSResolvingRegistrar to disallow registration of empty subdomains.


6.9 Company, Reputation, Membership - Code Duplications

Severity Status Remediation Comment
Minor Deferred Deferred as per Client's decision.

Description

Company, Reputation and Membership share most of the code with minor modifications for either the token configurations or initial token distribution. For example, Company and Reputation are almost identical.

Remediation

Consider de-duplicating and therefore increase the maintainability of the code-base to also avoid discrepancies like the one raised with issue 6.6.


7 Tool-Based Analysis

Several tools were used to perform automated analysis of the reviewed contracts. These issues were reviewed by the audit team, and relevant issues are listed in the Issue Details section.

7.1 MythX

MythX is a security analysis API for Ethereum smart contracts. It performs multiple types of analysis, including fuzzing and symbolic execution, to detect many common vulnerability types. The tool was used for automated vulnerability discovery for all audited contracts and libraries. More details on MythX can be found at mythx.io.

Where possible, we ran the full MythX analysis. MythX is still in beta, and where analysis failed, we fell back to running Mythril Classic, a large subset of the functionality of MythX.

7.2 Ethlint

Ethlint is an open source project for linting Solidity code. Only security-related issues were reviewed by the audit team.

The raw output of the Ethlint vulnerability scan can be found here.

7.3 Surya

Surya is a utility tool for smart contract systems. It provides a number of visual outputs and information about the structure of smart contracts. It also supports querying the function call graph in multiple ways to aid in the manual inspection and control flow analysis of contracts.

A complete list of functions with their visibility and modifiers can be found here.

Appendix 1 - Disclosure

ConsenSys Diligence (“CD”) typically receives compensation from one or more clients (the “Clients”) for performing the analysis contained in these reports (the “Reports”). The Reports may be distributed through other means, including via ConsenSys publications and other distributions.

The Reports are not an endorsement or indictment of any particular project or team, and the Reports do not guarantee the security of any particular project. This Report does not consider, and should not be interpreted as considering or having any bearing on, the potential economics of a token, token sale or any other product, service or other asset. Cryptographic tokens are emergent technologies and carry with them high levels of technical risk and uncertainty. No Report provides any warranty or representation to any Third-Party in any respect, including regarding the bugfree nature of code, the business model or proprietors of any such business model, and the legal compliance of any such business. No third party should rely on the Reports in any way, including for the purpose of making any decisions to buy or sell any token, product, service or other asset. Specifically, for the avoidance of doubt, this Report does not constitute investment advice, is not intended to be relied upon as investment advice, is not an endorsement of this project or team, and it is not a guarantee as to the absolute security of the project. CD owes no duty to any Third-Party by virtue of publishing these Reports.

PURPOSE OF REPORTS The Reports and the analysis described therein are created solely for Clients and published with their consent. The scope of our review is limited to a review of Solidity code and only the Solidity code we note as being within the scope of our review within this report. The Solidity language itself remains under development and is subject to unknown risks and flaws. The review does not extend to the compiler layer, or any other areas beyond Solidity that could present security risks. Cryptographic tokens are emergent technologies and carry with them high levels of technical risk and uncertainty.

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