Chamilo LMS Cross-Site Scripting Scanner

Chamilo LMS is an open-source e-learning and content management system used globally by educational institutions, corporations, and non-profit organizations for managing learning content and tracking learner progress. It provides a platform for teachers and instructors to deliver educational courses and for students to access materials and assessments online. The software is known for its intuitive interface, ease of integration, and extensive features aimed at enhancing the online learning experience. Chamilo's main goal is to improve accessibility to education and knowledge by promoting the use of open-source learning. It is widely used due to its scalability, flexibility, and ability to cater to diverse educational needs. Chamilo is also appreciated for its community engagement and multilingual support, making it accessible to a broad international audience.

Cross-Site Scripting (XSS) is a security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users. This vulnerability exploits the web application's lack of proper input validation or sanitization. By inserting crafted scripts, attackers can manipulate the content and behavior of web pages within the victim's browser. The impact can range from session hijacking to redirecting users to malicious websites. XSS vulnerabilities pose a significant risk as they can compromise user data, evade access controls, and execute arbitrary actions impersonating the victim user. Insecure coding practices or improper configuration often lead to such vulnerabilities, requiring attention to user input validation and encoding.

The Cross-Site Scripting vulnerability in Chamilo LMS occurs in the calendar module, specifically within the agenda_list.php file. The vulnerability is triggered when user-supplied data is not properly sanitized, allowing script execution within a trusted domain. The vulnerable parameter is found in the 'type' query, where malicious scripts can be inserted via the 'onmouseover' event. This allows attackers to execute unauthorized scripts by constructing a specially crafted URL. Successful exploitation can result in unauthorized actions, access to sensitive information, and disruption of course content. The vulnerability highlights a critical gap in input validation and requires prompt remediation to protect user data and application integrity.

When exploited, the Cross-Site Scripting vulnerability can lead to several detrimental effects. Attackers can execute arbitrary JavaScript code that performs actions on behalf of legitimate users without their knowledge or consent. This can lead to data theft, including login credentials, session tokens, and personal information. XSS can also facilitate the spread of malware by injecting malicious scripts into other parts of the application or external sites. Users' trust in the application may be eroded due to security breaches, leading to reputational damage. Furthermore, attackers can deface the user interface, manipulate content, or redirect users to phishing sites, causing operational disruptions in the learning environment. Immediate action is necessary to restore the confidence and security of users.

REFERENCES

• https://www.netsparker.com/web-applications-advisories/ns-21-001-cross-site-scripting-in-chamilo-lms/
• https://support.chamilo.org/projects/chamilo-18/wiki/Security_issues#Issue-45-2021-01-21-Moderate-impact-moderate-risk-XSS-vulnerability-in-agenda