Skip to content

Repository navigation

Scope of workflow operations is not validated

Critical
nickvergessen published GHSA-h3c9-cmh8-7qpj Mar 30, 2023

Package

Server (Nextcloud)

Affected versions

>= 24.0.0, >= 25.0.0

Patched versions

24.0.10, 25.0.4
Server (Nextcloud Enterprise)
>= 18.0.0, >= 19.0.0, >= 20.0.0, >= 21.0.0, >= 22.0.0, >= 23.0.0, >= 24.0.0, >= 25.0.0
20.0.14.12, 21.0.9.10, 22.2.10.10, 23.0.12.5, 24.0.10, 25.0.4

Description

Impact

A missing scope validation allowed users to create workflows which are designed to be only available for administrators. Some workflows are designed to be RCE by invoking defined scripts, in order to generate PDFs, invoking webhooks or running scripts on the server. Due to this combination depending on the available apps the issue can result in a RCE at the end.

Patches

It is recommended that the Nextcloud Server is upgraded to 24.0.10 or 25.0.4
It is recommended that the Nextcloud Enterprise Server is upgraded to 20.0.14.12 or 21.0.9.10 or 22.2.10.10 or 23.0.12.5 or 24.0.10 or 25.0.4
It is recommended that the Nextcloud Enterprise Server 18 or Nextcloud Enterprise Server 19 is manually patched.

Workarounds

  • Disable app workflow_scripts and workflow_pdf_converter

References

For more information

If you have any questions or comments about this advisory:

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
Required
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H

CVE ID

CVE-2023-26482

Weaknesses

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Learn more on MITRE.

Credits