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fief-server Server-Side Template Injection vulnerability

Critical severity GitHub Reviewed Published Jun 23, 2023 in fief-dev/fief • Updated Sep 5, 2023

Package

pip fief-server (pip)

Affected versions

>= 0.19.0, < 0.25.3

Patched versions

0.25.3

Description

Server-Side Template Injection

Overview of the Vulnerability

Server-Side Template Injection (SSTI) is a vulnerability within application templating engines where user input is improperly handled and is embedded into the template, possibly leading code being executed.

An attacker can use SSTI to execute code on the underlying system by manipulating values within the embedded template. When code is executed within the underlying system, it can allow an attacker to run permissioned commands under the exploited process, or exploit Cross-Site Scripting (XSS) to run code within the user's browser.

Business Impact

SSTI can lead to reputational damage for the business due to a loss in confidence and trust by users. If an attacker successfully executes code within the underlying system, it can result in data theft and indirect financial losses.

Steps to Reproduce

  1. Sign up and login to your account
  2. Use a browser to navigate to: email-templates {{URL}}
  3. put your payload in Edit Base template {{ cycler.__init__.__globals__.os.popen('id').read() }} and you will se it will execute.

Payload:
{{ cycler.__init__.__globals__.os.popen('id').read() }}

Proof of Concept (PoC)

The screenshot(s) below demonstrates the SSTI:

SSTI

References

@frankie567 frankie567 published to fief-dev/fief Jun 23, 2023
Published to the GitHub Advisory Database Jun 23, 2023
Reviewed Jun 23, 2023
Last updated Sep 5, 2023

Severity

Critical
10.0
/ 10

CVSS base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Weaknesses

No CWEs

CVE ID

No known CVE

GHSA ID

GHSA-hj8m-9fhf-v7jp

Source code

Credits

Checking history
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