CVE-2026-33704: CWE-434: Unrestricted Upload of File with Dangerous Type in chamilo chamilo-lms
Chamilo LMS is a learning management system. Prior to 1.11.38, any authenticated user (including students) can write arbitrary content to files on the server via the BigUpload endpoint. The key parameter controls the filename and the raw POST body becomes the file content. While .php extensions are filtered to .phps, the .pht extension passes through unmodified. On Apache configurations where .pht is handled as PHP, this leads to Remote Code Execution. This vulnerability is fixed in 1.11.38.
AI Analysis
Technical Summary
CVE-2026-33704 is a file upload vulnerability in Chamilo LMS before version 1.11.38. Authenticated users can write arbitrary files to the server through the BigUpload endpoint by specifying the filename via a key parameter and providing file content in the POST body. The system filters .php extensions but not .pht extensions, which on Apache servers configured to treat .pht files as PHP scripts, allows remote code execution. This vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type).
Potential Impact
The vulnerability allows authenticated users, including students, to upload files that can be executed as code on the server if the server treats .pht files as PHP scripts. This leads to remote code execution, potentially compromising the integrity and availability of the server. The CVSS score is 7.1 (high severity), reflecting the ease of exploitation with low privileges and the significant impact on integrity and availability.
Mitigation Recommendations
Upgrade Chamilo LMS to version 1.11.38 or later, where this vulnerability is fixed. Since this is an application-level vulnerability and the fix is available in the updated version, applying the official update is the recommended remediation. Patch status is confirmed fixed in version 1.11.38.
CVE-2026-33704: CWE-434: Unrestricted Upload of File with Dangerous Type in chamilo chamilo-lms
Description
Chamilo LMS is a learning management system. Prior to 1.11.38, any authenticated user (including students) can write arbitrary content to files on the server via the BigUpload endpoint. The key parameter controls the filename and the raw POST body becomes the file content. While .php extensions are filtered to .phps, the .pht extension passes through unmodified. On Apache configurations where .pht is handled as PHP, this leads to Remote Code Execution. This vulnerability is fixed in 1.11.38.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-33704 is a file upload vulnerability in Chamilo LMS before version 1.11.38. Authenticated users can write arbitrary files to the server through the BigUpload endpoint by specifying the filename via a key parameter and providing file content in the POST body. The system filters .php extensions but not .pht extensions, which on Apache servers configured to treat .pht files as PHP scripts, allows remote code execution. This vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type).
Potential Impact
The vulnerability allows authenticated users, including students, to upload files that can be executed as code on the server if the server treats .pht files as PHP scripts. This leads to remote code execution, potentially compromising the integrity and availability of the server. The CVSS score is 7.1 (high severity), reflecting the ease of exploitation with low privileges and the significant impact on integrity and availability.
Mitigation Recommendations
Upgrade Chamilo LMS to version 1.11.38 or later, where this vulnerability is fixed. Since this is an application-level vulnerability and the fix is available in the updated version, applying the official update is the recommended remediation. Patch status is confirmed fixed in version 1.11.38.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-03-23T17:06:05.746Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 69d9d9721cc7ad14da3f862f
Added to database: 4/11/2026, 5:17:38 AM
Last enriched: 4/18/2026, 2:34:00 PM
Last updated: 5/26/2026, 6:54:01 PM
Views: 74
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