CVE-2025-50194: Chamilo LMS RCE Vulnerability

CVE-2025-50194 Overview

CVE-2025-50194 is an OS Command Injection vulnerability affecting Chamilo, a popular open-source learning management system (LMS). The vulnerability exists in the /main/cron/lang/check_parse_lang.php script in versions prior to 1.11.30, allowing authenticated attackers with high privileges to execute arbitrary operating system commands on the underlying server.

Critical Impact
Successful exploitation enables attackers to execute arbitrary system commands, potentially leading to complete server compromise, data exfiltration, and lateral movement within the network infrastructure hosting the LMS.

Affected Products

Chamilo LMS versions prior to 1.11.30
Chamilo LMS installations using the vulnerable check_parse_lang.php cron functionality
All deployments with network-accessible administrative interfaces

Discovery Timeline

2026-03-02 - CVE-2025-50194 published to NVD
2026-03-03 - Last updated in NVD database

Technical Details for CVE-2025-50194

Vulnerability Analysis

The vulnerability stems from improper input validation in Chamilo LMS's language handling functionality. The affected component fails to adequately sanitize user-supplied input before incorporating it into system commands, creating a classic command injection attack surface. This flaw allows authenticated users with administrative privileges to inject malicious shell commands through crafted input parameters.

The attack requires network access to the vulnerable endpoint and high-level privileges within the Chamilo application. While the confidentiality impact is limited, successful exploitation can result in significant integrity and availability impacts to the affected system.

Root Cause

The root cause is classified as CWE-78 (Improper Neutralization of Special Elements used in an OS Command). The vulnerable code path accepts user input—specifically the English name parameter for sublanguage operations—and passes it to system-level functions without proper sanitization of dangerous characters that could be interpreted as shell metacharacters.

Attack Vector

The vulnerability is exploitable over the network by authenticated attackers with administrative privileges. The attack flow involves:

An authenticated administrator accesses the vulnerable language management functionality
Malicious input containing shell metacharacters is submitted through the english_name parameter
The unsanitized input is processed by system-level functions
Arbitrary commands are executed with the privileges of the web server process

The following patch demonstrates how Chamilo addressed this vulnerability by implementing proper input sanitization:

php

 
if (isset($_POST['SubmitAddNewLanguage'])) {
    $original_name = $_POST['original_name'];
-    $english_name = $_POST['english_name'];
    $isocode = $_POST['isocode'];
-    $english_name = str_replace(' ', '_', $english_name);
+    $english_name = api_replace_dangerous_char($_POST['english_name']);
    $isocode = str_replace(' ', '_', $isocode);

    $sublanguage_available = $_POST['sub_language_is_visible'];

Source: GitHub Commit

The fix replaces the insufficient str_replace() function with api_replace_dangerous_char(), which properly sanitizes special characters that could be used for command injection.

Detection Methods for CVE-2025-50194

Indicators of Compromise

Unusual process spawning from the web server process (e.g., PHP-FPM or Apache)
Unexpected network connections originating from the Chamilo application server
Suspicious entries in web server access logs targeting /main/cron/lang/check_parse_lang.php or language administration endpoints
Anomalous system command execution patterns in process monitoring logs

Detection Strategies

Monitor web application logs for requests to /main/cron/lang/check_parse_lang.php with unusual parameters
Implement Web Application Firewall (WAF) rules to detect command injection patterns in POST parameters
Deploy endpoint detection solutions to identify unexpected child processes spawned by web server processes
Analyze HTTP request payloads for shell metacharacters (;, |, &, $(), backticks) in the english_name parameter

Monitoring Recommendations

Enable verbose logging for Chamilo administrative actions
Configure SIEM alerts for command injection attack signatures targeting LMS infrastructure
Monitor server resource utilization for anomalies that may indicate post-exploitation activity
Implement file integrity monitoring on the Chamilo installation directory

How to Mitigate CVE-2025-50194

Immediate Actions Required

Upgrade Chamilo LMS to version 1.11.30 or later immediately
Review administrative user accounts and remove any unauthorized or unnecessary privileged accounts
Audit access logs for any previous exploitation attempts targeting language management functionality
Implement network segmentation to limit exposure of administrative interfaces

Patch Information

Chamilo has released version 1.11.30 which addresses this vulnerability. The patch implements proper input sanitization using the api_replace_dangerous_char() function to neutralize dangerous characters before processing. Organizations should apply this update as soon as possible.

For detailed patch information, refer to the GitHub Security Advisory GHSA-xrr6-wv8p-5v3p and the official release notes for v1.11.30.

Workarounds

Restrict network access to Chamilo administrative interfaces using firewall rules or VPN requirements
Disable or remove the vulnerable cron script /main/cron/lang/check_parse_lang.php if not required for operations
Implement additional WAF rules to block requests containing shell metacharacters in language-related parameters
Enforce strict access controls to limit administrative privileges to essential personnel only

bash

# Configuration example: Restrict access to cron scripts in Apache
<Directory "/var/www/chamilo/main/cron">
    Require ip 127.0.0.1
    Require ip 10.0.0.0/8
</Directory>

# Or block access entirely if not needed
<Location "/main/cron">
    Require all denied
</Location>