CVE-2024-56201: Palletsprojects Jinja RCE Vulnerability

CVE-2024-56201 is a remote code execution vulnerability in Palletsprojects Jinja 3.x that allows attackers controlling template content and filename to execute arbitrary Python code, bypassing sandbox protections. This article covers technical details, affected versions, exploitation risks, and available patches.

CVE-2024-56201 Overview

Jinja is an extensible templating engine. In versions on the 3.x branch prior to 3.1.5, a bug in the Jinja compiler allows an attacker that controls both the content and filename of a template to execute arbitrary Python code, regardless of if Jinja's sandbox is used. This vulnerability impacts users of applications which execute untrusted templates where the template author can also choose the template filename.

Critical Impact
Potential arbitrary code execution

Affected Products

palletsprojects jinja

Discovery Timeline

Not Available - Vulnerability discovered by Not Available
Not Available - Responsible disclosure to palletsprojects
Not Available - CVE CVE-2024-56201 assigned
Not Available - palletsprojects releases security patch
2024-12-23T16:15:07.410 - CVE CVE-2024-56201 published to NVD
2025-09-22T17:45:28.710 - Last updated in NVD database

Technical Details for CVE-2024-56201

Vulnerability Analysis

The vulnerability arises when an attacker controls both the filename and content of a Jinja template, enabling them to execute arbitrary Python code, even in situations where Jinja's sandbox is intended to prevent such execution.

Root Cause

Inadequate restrictions on the template compiler in Jinja allowed execution of untrusted code when both filename and content of the template were controlled by an attacker.

Attack Vector

Local

python

# Example exploitation code (sanitized)
from jinja2 import Template

# Potentially untrusted input
template_filename = "user_generated_template"
template_content = "{{ loop.__init__.__globals__['os'].system('ls') }}"

# Dangerous compilation
template = Template(template_content)
rendered_template = template.render()

Detection Methods for CVE-2024-56201

Indicators of Compromise

Unexpected process execution in applications using Jinja.
Logs showing unusual template filenames being used.
Presence of files with malicious code injections.

Detection Strategies

Implement monitoring for changes in the Jinja template files and execution of system commands within application logs. Use behavior-based detection to identify unknown processes triggered by template rendering.

Monitoring Recommendations

Enable verbose logging for template rendering activities.
Set up alerts for changes in template filenames or content in deployment environments using Jinja.

How to Mitigate CVE-2024-56201

Immediate Actions Required

Update Jinja to version 3.1.5 or later.
Review and sanitize user-supplied data used as template content.
Restrict access to the template directory to trusted users only.

Patch Information

The patch fixing this vulnerability is available in version 3.1.5. Users should upgrade to this or a later version to remediate the issue.

Workarounds

Implement input validation and ensure only trusted users can generate templates.

bash

# Configuration example
pip install --upgrade jinja2==3.1.5