Chamilo LMS, an open-source learning management system, was found to have a Server-Side Request Forgery (SSRF) vulnerability identified as CVE-2024-50337, affecting versions prior to 1.11.28. The vulnerability resides in the OpenId authentication function, which improperly handles URL requests, allowing unauthenticated attackers to coerce the server into sending HTTP requests to arbitrary URLs. This SSRF flaw enables attackers to potentially access internal services that are otherwise inaccessible externally, perform reconnaissance on internal network infrastructure, or interact with external systems under the guise of the vulnerable server. The vulnerability does not require any authentication or user interaction, making it easier to exploit remotely. The CVSS 3.1 base score of 5.3 reflects a medium severity, with the main impact being limited confidentiality exposure due to the ability to retrieve data from internal services. There is no direct impact on data integrity or service availability. The vulnerability was publicly disclosed and patched in Chamilo LMS version 1.11.28. No known exploits have been reported in the wild to date, but the nature of SSRF vulnerabilities means they can be leveraged for further attacks such as internal network scanning or pivoting. The patch involves proper validation and sanitization of URLs in the OpenId function to prevent arbitrary request redirection.

The primary impact of CVE-2024-50337 is unauthorized internal network reconnaissance and potential data exposure from internal or protected resources accessible by the vulnerable Chamilo LMS server. Attackers can exploit this SSRF to bypass firewall rules and access internal services that are not exposed externally, potentially revealing sensitive information. While the vulnerability does not directly allow data modification or denial of service, it can be a stepping stone for more advanced attacks such as exploiting other internal vulnerabilities or exfiltrating sensitive data. Educational institutions and organizations relying on Chamilo LMS may face risks of information leakage or network mapping by attackers. The ease of exploitation without authentication increases the threat level, especially in environments where the LMS server has privileged network access. However, the lack of known active exploitation and limited impact on integrity and availability somewhat reduces the immediate risk severity.

Organizations using Chamilo LMS should immediately upgrade to version 1.11.28 or later, where the SSRF vulnerability has been patched. In addition to patching, administrators should implement network-level controls to restrict outbound HTTP/HTTPS requests from the LMS server to only trusted destinations, minimizing the risk of SSRF exploitation. Web application firewalls (WAFs) can be configured to detect and block suspicious SSRF patterns, such as requests to internal IP ranges or unusual URL parameters. Monitoring and logging outbound requests from the LMS server can help detect exploitation attempts. If upgrading is not immediately possible, disabling the OpenId function temporarily or restricting its usage can reduce exposure. Regular security assessments and penetration testing focusing on SSRF and related vulnerabilities should be conducted to identify and remediate similar issues proactively.