CVE-2025-13828: Composer Privilege Escalation Vulnerability

CVE-2025-13828 Overview

CVE-2025-13828 is a critical missing authorization vulnerability affecting Mautic, an open-source marketing automation platform. The vulnerability allows a non-privileged user to install and remove arbitrary Composer packages in Composer-based installations, even when the "enable composer based update" flag is explicitly disabled in the update settings. This authorization bypass enables low-privileged users to inject malicious code into the platform to escalate their privileges.

Critical Impact

Low-privileged users can install malicious Composer packages to achieve privilege escalation, potentially gaining full control of the Mautic platform and underlying server infrastructure.

Affected Products

• Mautic (Composer-based installations)

Discovery Timeline

• 2025-12-02 - CVE-2025-13828 published to NVD
• 2025-12-02 - Last updated in NVD database

Technical Details for CVE-2025-13828

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), indicating that the application fails to properly enforce authorization checks when processing Composer package management operations. The security control intended to restrict Composer-based updates through the administrative settings panel does not function correctly, leaving the package installation and removal endpoints accessible to low-privileged users.

The vulnerability is network-exploitable, meaning an authenticated attacker with low privileges can remotely exploit this flaw without requiring any user interaction. The successful exploitation leads to complete compromise of confidentiality, integrity, and availability of both the vulnerable system and potentially connected systems.

Root Cause

The root cause of CVE-2025-13828 is the absence of proper authorization checks on Composer package management functionality. While Mautic provides an administrative setting to disable Composer-based updates, this configuration flag is not properly validated or enforced at the code level when handling package installation or removal requests. This allows users without appropriate permissions to bypass the intended security control and execute arbitrary Composer operations.

Attack Vector

An attacker with a low-privileged account on a Mautic platform can exploit this vulnerability through the following attack path:

1. The attacker authenticates to Mautic with a low-privileged user account
2. Despite the "enable composer based update" setting being disabled, the attacker directly accesses the Composer package management functionality
3. The attacker installs a malicious Composer package containing backdoor code or privilege escalation payloads
4. The malicious code executes within the context of the Mautic application, allowing the attacker to escalate privileges

The vulnerability manifests in the authorization logic that governs access to Composer operations. The application fails to verify whether the authenticated user has the appropriate permissions and whether the administrative settings permit such operations. For detailed technical information, refer to the GitHub Security Advisory.

Detection Methods for CVE-2025-13828

Indicators of Compromise

• Unexpected Composer package installations in the Mautic vendor/ directory
• Unfamiliar or suspicious entries in composer.json or composer.lock files
• Audit logs showing Composer operations performed by non-administrative users
• New or modified PHP files in vendor directories with recent timestamps

Detection Strategies

• Monitor file system changes in the Mautic installation directory, particularly vendor/, composer.json, and composer.lock
• Implement application-level logging to track all Composer-related API calls and the associated user context
• Deploy endpoint detection solutions to identify unauthorized package management activities
• Review web server access logs for requests to Composer management endpoints from non-admin sessions

Monitoring Recommendations

• Enable detailed audit logging for all user actions within the Mautic administrative interface
• Configure file integrity monitoring (FIM) on critical Mautic directories
• Set up alerts for any changes to composer.json or composer.lock files outside of scheduled maintenance windows
• Monitor for unusual PHP process spawning that may indicate malicious package execution

How to Mitigate CVE-2025-13828

Immediate Actions Required

• Review recent Composer package changes in your Mautic installation for any unauthorized additions
• Audit user accounts and remove unnecessary low-privileged accounts with access to the platform
• Restrict network access to the Mautic administrative interface to trusted IP ranges
• Monitor the GitHub Security Advisory for official patches and updates

Patch Information

Organizations should monitor the official Mautic security channels and the GitHub Security Advisory for patch releases addressing this vulnerability. Apply security updates immediately upon availability and verify the patch has been successfully deployed.

Workarounds

• Implement web application firewall (WAF) rules to block access to Composer management endpoints for non-administrative users
• Use server-level access controls to restrict write permissions to the vendor/ directory and composer.json file
• Consider temporarily disabling low-privileged user accounts until a patch is available
• Deploy additional authentication layers (such as IP whitelisting or VPN requirements) for accessing the Mautic administrative interface