Is this vulnerability remotely exploitable over the internet?

Yes. Any user who can authenticate to the Chamilo LMS instance and reach the BigUpload endpoint can potentially exploit the issue, assuming the server is reachable over the network and executes `.pht` files.

What level of access does an attacker need?

Only a valid authenticated account is required, including low-privilege roles such as students. No administrative permissions are necessary if the vulnerable upload endpoint is accessible to regular users.

What is the safest general fix pattern?

Implement a strict upload pipeline that uses server-generated file names, performs robust allowlist-based extension checks, stores uploaded files outside executable directories, and configures the web server so uploaded content cannot be executed as code. Treat all uploads as untrusted data, not executable resources.

Severity:

HIGH RISK

(7.1)

Unrestricted File Upload (CWE-434) via BigUpload Endpoint in Chamilo LMS

CVE-2026-33704

Published:

Apr 10, 2026

Status:

Analyzed

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

NDV

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Vulnerability Type

Category:

Unrestricted File Upload

CWE:

CWE-434

Impact:

Remote Code Execution (RCE) on vulnerable PHP/Apache deployments

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

Vulnerability Type

Category:

Unrestricted File Upload

CWE:

CWE-434

Impact:

Remote Code Execution (RCE) on vulnerable PHP/Apache deployments

Severity:

HIGH RISK

(7.1)

CVSS Version:

3.1

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Unrestricted File Upload (CWE-434) via BigUpload Endpoint in Chamilo LMS

Summary

Affected Context

Exploit Preconditions

Why This Happens

Potential Impact

General Mitigation Guidance

How Teams Detect Issues Like This

Frequently Asked Questions

Source

Recent Vulnerabilities

HIGH RISK

HIGH

(8.8)

PHP Code Injection via File Upload (CWE-94) in Aero CMS Admin Post Creation

HIGH RISK

HIGH

(8.8)

Code Injection (CWE-94) via Module Parameters in Evolution CMS

Vulnerability Type

Vulnerability Type

Vulnerability Type

Catch This CVE While Code Is Being Written

Ship clean & secure code faster

Ship clean & secure code faster

Ship clean & secure code faster

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