CVE-2025-59543 in LMS
Summary
by MITRE • 03/06/2026
Chamilo is a learning management system. Prior to version 1.11.34, there is a stored cross-site scripting (XSS) vulnerability. By injecting malicious JavaScript into the course description field, an attacker with a low-privileged account (e.g., trainer) can execute arbitrary JavaScript code in the context of any other user viewing the course information page, including administrators. This allows an attacker to exfiltrate sensitive session cookies or tokens, resulting in account takeover (ATO) of higher-privileged users. This issue has been patched in version 1.11.34.
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Analysis
by VulDB Data Team • 03/06/2026
The vulnerability identified as CVE-2025-59543 represents a critical stored cross-site scripting flaw within the Chamilo learning management system that affects versions prior to 1.11.34. This vulnerability exists in the course description field processing functionality, where the system fails to properly sanitize user input before rendering it in web pages. The flaw allows malicious actors with low-privileged accounts such as trainers to inject persistent JavaScript payloads that execute whenever other users, including administrators, view the affected course information pages. This stored XSS vulnerability operates at the application layer and demonstrates a significant security weakness in the input validation and output encoding mechanisms employed by the platform.
The technical exploitation of this vulnerability follows a well-established attack pattern that aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation. Attackers can craft malicious JavaScript code within the course description field, which gets stored in the database and subsequently executed in the browser context of any user who accesses the affected page. The attack vector is particularly dangerous because it does not require direct user interaction beyond accessing the compromised course information page. The vulnerability's impact extends beyond simple data theft, as it can be leveraged for complete account takeover operations by stealing session cookies, authentication tokens, or other sensitive credentials that would otherwise be protected by standard browser security mechanisms. This creates a severe privilege escalation scenario where low-privileged users can gain access to administrative functions and sensitive data.
The operational impact of CVE-2025-59543 is substantial for organizations relying on Chamilo for educational content management and user authentication. The vulnerability creates a persistent backdoor that can be exploited by attackers to monitor user activities, steal confidential information, manipulate course content, and potentially gain access to sensitive student data. The attack surface is particularly wide because administrators frequently access course information pages, making them prime targets for exploitation. This vulnerability directly maps to attack techniques described in the MITRE ATT&CK framework under T1566 - Phishing and T1078 - Valid Accounts, as it enables attackers to leverage legitimate user credentials through session hijacking and account takeover methods. Organizations using Chamilo without the patch are vulnerable to prolonged surveillance and data compromise attacks that could go undetected for extended periods.
The remediation for this vulnerability requires immediate deployment of Chamilo version 1.11.34 or later, which includes proper input sanitization and output encoding mechanisms that prevent the execution of malicious JavaScript code. System administrators should implement comprehensive input validation that filters out potentially dangerous characters and patterns commonly associated with XSS attacks. Additionally, organizations should consider implementing Content Security Policy (CSP) headers as an additional defense-in-depth measure to further mitigate the risk of XSS exploitation. Regular security audits and penetration testing should be conducted to identify similar vulnerabilities in other web applications, and user privilege management should be reviewed to ensure that only authorized individuals have access to course creation and modification functions. The vulnerability also highlights the importance of maintaining up-to-date software versions and implementing robust security monitoring to detect potential exploitation attempts.