Authenticated code execution via unrestricted PHP upload
Published Nov 28, 2023 · Updated Jun 5, 2025
Unrestricted file upload in Chamilo LMS 1.11.24 and earlier allows remote authenticated users to execute code through crafted uploads. The upload path in main/inc/ajax/exercise.ajax.php appends attacker-named chunks to the web-accessible app/cache directory without rejecting dangerous filenames or file types, enabling .htaccess modification and PHP web-shell execution. A learner account and access to view an open course are sufficient; course enrollment is not required, and exploitation runs code as the web-server user.
Summary
What happened
Unrestricted file upload in Chamilo LMS 1.11.24 and earlier allows remote authenticated users to execute code through crafted uploads. The upload path in main/inc/ajax/exercise.ajax.php appends attacker-named chunks to the web-accessible app/cache directory without rejecting dangerous filenames or file types, enabling .htaccess modification and PHP web-shell execution. A learner account and access to view an open course are sufficient; course enrollment is not required, and exploitation runs code as the web-server user.
The record
- CVE
- CVE-2023-4225
- Published
- Nov 28, 2023
- Updated
- Jun 5, 2025
- Vendor
- Chamilo
- Product
- Chamilo LMS
- Classifications
- CWE-434, CAPEC-650, T1505.003
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Nov 28, 2023CVE publishedPublication date reported by the CVE source.
- Jun 5, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <=1.11.24
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- STAR Labs exercise.ajax.php proof of conceptfunctional · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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