CVE-2023-3545: Chamilo LMS Htaccess File Upload Security Bypass

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-11-28 · updated 2026-06-17
Weakness: CWE-178

Description

Improper sanitisation in `main/inc/lib/fileUpload.lib.php` in Chamilo LMS <= v1.11.20 on Windows and Apache installations allows unauthenticated attackers to bypass file upload security protections and obtain remote code execution via uploading of `.htaccess` file. This vulnerability may be exploited by privileged attackers or chained with unauthenticated arbitrary file write vulnerabilities, such as CVE-2023-3533, to achieve remote code execution.

Affected products

Chamilo: through 1.11.20

References

https://github.com/chamilo/chamilo-lms/commit/dc7bfce429fbd843a95a57c184b6992c4d709549
https://starlabs.sg/advisories/23/23-3545/
https://support.chamilo.org/projects/chamilo-18/wiki/security_issues#Issue-125-2023-07-13-Critical-impact-Moderate-risk-Htaccess-File-Upload-Security-Bypass-on-Windows-CVE-2023-3545
https://github.com/chamilo/chamilo-lms/commit/dc7bfce429fbd843a95a57c184b6992c4d709549
https://starlabs.sg/advisories/23/23-3545/
https://support.chamilo.org/projects/chamilo-18/wiki/security_issues#Issue-125-2023-07-13-Critical-impact-Moderate-risk-Htaccess-File-Upload-Security-Bypass-on-Windows-CVE-2023-3545

Get alerted when CVE-2023-3545 or the next vulnerability affects your stack