CVE-2025-50187: Chamilo LMS RCE Vulnerability

CVE-2025-50187 Overview

CVE-2025-50187 is a critical remote code execution vulnerability affecting Chamilo, an open-source learning management system (LMS). The vulnerability exists because a parameter from SOAP requests is evaluated without proper filtering, enabling attackers to execute arbitrary code on vulnerable servers. This flaw allows unauthenticated remote attackers to fully compromise Chamilo LMS installations, potentially gaining complete control over the underlying server and any sensitive educational data stored within the platform.

Critical Impact

Unauthenticated remote attackers can achieve arbitrary code execution on Chamilo LMS servers via malicious SOAP requests, potentially compromising student data, course materials, and the entire server infrastructure.

Affected Products

• Chamilo LMS versions prior to 1.11.28
• All Chamilo LMS installations exposed via network with SOAP endpoints accessible

Discovery Timeline

• 2026-03-02 - CVE-2025-50187 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2025-50187

Vulnerability Analysis

This vulnerability is classified as CWE-95 (Improper Neutralization of Directives in Dynamically Evaluated Code), commonly known as code injection or eval injection. The flaw resides in Chamilo's SOAP interface, where user-supplied input from SOAP requests is passed directly to an evaluation function without adequate sanitization or validation.

When processing SOAP requests, the vulnerable code path accepts parameters that are dynamically evaluated by the PHP interpreter. Because no filtering mechanism exists to prevent malicious input, an attacker can craft a specially formed SOAP request containing arbitrary PHP code. The server then executes this injected code with the privileges of the web server process, typically granting the attacker the ability to read sensitive files, modify data, establish persistence, or pivot to other systems on the network.

The network-accessible nature of the vulnerability combined with the lack of authentication requirements makes this particularly dangerous for internet-facing Chamilo deployments commonly used by educational institutions.

Root Cause

The root cause is the direct evaluation of untrusted user input from SOAP request parameters. The application fails to implement proper input validation, sanitization, or whitelisting before passing the parameter to a code evaluation function. This represents a fundamental secure coding violation where user-controlled data flows directly into a dangerous sink function capable of executing arbitrary code.

Attack Vector

The attack is executed remotely over the network by sending specially crafted SOAP requests to the vulnerable Chamilo LMS endpoint. The attacker does not require any authentication or prior access to the system. The exploitation process involves:

1. Identifying a Chamilo LMS instance with accessible SOAP endpoints
2. Crafting a malicious SOAP request containing PHP code injection payload in the vulnerable parameter
3. Sending the request to the target server's SOAP handler
4. The injected code executes server-side with web server privileges

The vulnerability mechanism centers on unfiltered parameter evaluation in SOAP request handling. When the application receives a SOAP request, the vulnerable parameter is processed by a PHP evaluation function without sanitization, allowing arbitrary PHP code to be executed. For detailed technical analysis, refer to the GitHub Security Advisory GHSA-356v-7xg2-3678.

Detection Methods for CVE-2025-50187

Indicators of Compromise

• Unusual outbound network connections originating from the web server process
• Unexpected PHP processes or child processes spawned by the web server
• Modified or newly created files in web-accessible directories, particularly webshells
• Anomalous SOAP requests in web server access logs targeting Chamilo endpoints
• Evidence of reconnaissance or lateral movement originating from the Chamilo server

Detection Strategies

• Monitor web server access logs for suspicious SOAP requests containing encoded payloads or unusual characters
• Implement Web Application Firewall (WAF) rules to detect and block code injection patterns in SOAP parameters
• Deploy endpoint detection and response (EDR) solutions to identify post-exploitation activity such as process injection or credential theft
• Analyze network traffic for command-and-control communications from web server processes

Monitoring Recommendations

• Enable verbose logging for the Chamilo SOAP interface and web server access logs
• Configure SIEM alerts for patterns indicative of code injection attempts in HTTP POST bodies
• Establish baseline behavior for the Chamilo application and alert on deviations such as new network connections or file system modifications
• Regularly review web server process execution for unexpected child processes

How to Mitigate CVE-2025-50187

Immediate Actions Required

• Upgrade Chamilo LMS to version 1.11.28 or later immediately
• If immediate patching is not possible, disable or restrict access to SOAP endpoints via web server configuration or firewall rules
• Audit systems for indicators of compromise, particularly if the instance was publicly accessible
• Review access logs for evidence of exploitation attempts prior to patching
• Implement network segmentation to limit the blast radius if the server is compromised

Patch Information

Chamilo has released version 1.11.28 which addresses this vulnerability. Administrators should upgrade to this version or later as soon as possible. The patch can be obtained from the official Chamilo LMS Release v1.11.28. Review the GitHub Security Advisory GHSA-356v-7xg2-3678 for complete details on the vulnerability and remediation.

Workarounds

• Restrict access to SOAP endpoints at the web server or network firewall level to trusted IP addresses only
• Place Chamilo LMS behind a Web Application Firewall with rules to detect and block code injection attempts
• Disable SOAP functionality entirely if not required for your deployment
• Implement network segmentation to isolate the Chamilo server from sensitive internal resources

# Apache configuration to restrict SOAP endpoint access
<Location "/main/webservices/">
    Require ip 10.0.0.0/8
    Require ip 192.168.0.0/16
</Location>