Executive brief
Chamilo LMS is a learning management system used for online course delivery and student management. An unauthenticated attacker can upload and execute arbitrary code on the server through the CStudio upload functionality without needing to log in, allowing complete system compromise including data theft, service disruption, and malware deployment.
Technical details
The vulnerability is a combination of improper file upload validation (CWE-434), path traversal (CWE-22), and code injection (CWE-94) in the CStudio upload mechanism. The CStudio component fails to properly restrict uploaded file types and validate upload paths, allowing an unauthenticated attacker to upload executable code (e.g., PHP, JSP) to a web-accessible directory. No authentication is required, attack complexity is low, and no user interaction is needed. An attacker can achieve remote code execution with full system privileges, potentially exfiltrating sensitive data, modifying content, or disrupting service availability. A patch is available in version 2.0.1.
Affected products
- Chamilo Chamilo LMS <= 2.0.0
Timeline
- 2026-06-09: disclosed: Initially published on GitHub
- 2026-06-09: patched: Patched in version 2.0.1 (commit 4bdba1b)
- 2026-09-17: advisory: Added to GitHub Advisory Database