CVE-2024-46986: Camaleon CMS Arbitrary File Write Flaw

CVE-2024-46986 Overview

Camaleon CMS is a Ruby on Rails-based content management system. CVE-2024-46986 is an arbitrary file write vulnerability in the upload method of the MediaController. Authenticated users can write arbitrary files to any location on the web server, constrained only by the underlying filesystem permissions. Attackers who write a Ruby file into the config/initializers/ subfolder of the Rails application can achieve delayed remote code execution. The flaw is tracked under [CWE-22] (Path Traversal) and [CWE-74] (Improper Neutralization). Camaleon CMS release 2.8.2 addresses the issue.

Critical Impact

Authenticated attackers can write arbitrary files to the server filesystem and achieve remote code execution by dropping malicious Ruby initializers into the Rails application directory.

Affected Products

• Tuzitio Camaleon CMS versions prior to 2.8.2
• Ruby on Rails applications embedding vulnerable Camaleon CMS releases
• Web servers hosting Camaleon CMS with writable application directories

Discovery Timeline

• 2024-09-18 - CVE-2024-46986 published to the National Vulnerability Database
• 2025-04-17 - Last updated in NVD database

Technical Details for CVE-2024-46986

Vulnerability Analysis

The vulnerability resides in the upload action of the MediaController within Camaleon CMS. The handler accepts user-supplied path components without sufficient neutralization, allowing attackers to traverse outside the intended upload directory. Authenticated users with media upload privileges supply path values that escape the media root and resolve to arbitrary filesystem locations. Because the application runs under the same user context as the Rails worker, any path writable by that account becomes a target. The flaw is classified as both Path Traversal and Improper Neutralization of Special Elements in Output.

Root Cause

The upload method fails to canonicalize and validate destination paths before writing uploaded content. User-controlled input flows into a filesystem write operation without enforcing a base-directory boundary check. Rails treats files placed under config/initializers/ as executable bootstrap code on the next application load, which converts a file write primitive into code execution.

Attack Vector

An authenticated attacker submits a crafted upload request to the MediaController#upload endpoint with a manipulated filename or path parameter. The malicious payload contains directory traversal sequences that redirect the write operation to config/initializers/. The attacker stages a Ruby file containing arbitrary code. On the next Rails application restart or reload, the initializer executes with the privileges of the Rails process. Refer to the GitHub Security Lab advisory and the CodeQL Ruby Path Injection Guide for technical analysis.

Detection Methods for CVE-2024-46986

Indicators of Compromise

• Unexpected .rb files appearing in config/initializers/, lib/, or other Rails application subdirectories
• HTTP POST requests to Camaleon CMS media upload endpoints containing ../ sequences or absolute paths in filename parameters
• Rails application logs showing media uploads with filenames resolving outside the configured media root
• Process spawns originating from the Rails worker that do not match normal request handling patterns

Detection Strategies

• Inspect web server access logs for upload requests targeting MediaController with suspicious path traversal payloads in form data
• Monitor filesystem activity on Rails application directories, particularly write events to config/, lib/, and app/ paths
• Compare deployed application files against the known-good release manifest to flag unauthorized additions
• Apply static analysis rules such as the CodeQL Ruby Path Injection query to identify exploitable sinks

Monitoring Recommendations

• Enable audit logging on the directory tree of the Rails application root with file integrity monitoring
• Alert on creation of new Ruby files in config/initializers/ outside of deployment windows
• Track authentication events for accounts with media upload permissions and correlate against upload activity volume

How to Mitigate CVE-2024-46986

Immediate Actions Required

• Upgrade Camaleon CMS to version 2.8.2 or later as instructed in the GitHub advisory GHSA-wmjg-vqhv-q5p5
• Audit existing Rails application directories for unauthorized .rb files introduced through media upload paths
• Rotate credentials for any user accounts with media upload privileges following remediation
• Restart the Rails application after patching to ensure no malicious initializers remain loaded

Patch Information

The maintainer released Camaleon CMS 2.8.2, which addresses the arbitrary file write in the upload method of the MediaController. See the Reddit release announcement and the GitHub security advisory for upgrade details. Refer to the OWASP Path Traversal reference for defense-in-depth guidance.

Workarounds

• No vendor-supplied workarounds exist; upgrading to 2.8.2 is the only supported remediation
• As a temporary compensating control, restrict media upload privileges to trusted administrative accounts only
• Run the Rails worker under a least-privileged user account with read-only access to config/initializers/ and related application directories

# Configuration example: upgrade Camaleon CMS via Bundler
bundle update camaleon_cms --conservative
bundle exec rails restart