HIGH CVSS 7.2
Published: 2021-04-30

CVE-2021-31933

chamilo chamilo Security Advisory (CVE-2021-31933)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-31933 impacting chamilo chamilo. Evaluated with CVSS Base Score of 7.2 (HIGH).

Original NVD Description

Source: NIST NVD
A remote code execution vulnerability exists in Chamilo through 1.11.14 due to improper input sanitization of a parameter used for file uploads, and improper file-extension filtering for certain filenames (e.g., .phar or .pht). A remote authenticated administrator is able to upload a file containing arbitrary PHP code into specific directories via main/inc/lib/fileUpload.lib.php directory traversal to achieve PHP code execution.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
High (PR:H)
Administrative credentials required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product chamilo / chamilo
Affected Versions *
Weakness Enumeration CWE-706

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2021-31933 impacting chamilo chamilo.

⚡ Nuclei Detection Template (YAML) cve-2021-31933.yaml
id: cve-2021-31933

info:
  name: chamilo chamilo - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2021-31933 affecting chamilo chamilo.
    Evaluation: A remote code execution vulnerability exists in Chamilo through 1.11.14 due to improper input sanitization of a parameter used for file uploads, and i...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-31933
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 7.2
    cve-id: CVE-2021-31933
    cwe-id: CWE-706
  tags: cve,cve-2021-31933,chamilo,chamilo,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "chamilo"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-31933.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-31933
# Target: chamilo chamilo | CVSS: 7.2 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-31933 (chamilo chamilo)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against chamilo chamilo scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2021-31933.sh
# Recommended Remediation & Patching Commands for CVE-2021-31933
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install chamilo 2>/dev/null || \
sudo dnf upgrade chamilo 2>/dev/null || \
sudo yum update chamilo

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i chamilo 2>/dev/null || rpm -qa | grep -i chamilo

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2021-31933 in chamilo chamilo?

Review vendor-specific security notices and update chamilo chamilo packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2021-31933?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2021-31933?

CVE-2021-31933 is classified with a CVSS 3.1 Base Score of 7.2 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.2
HIGH SEVERITY
CVE ID CVE-2021-31933
Weakness CWE-706
Vendor chamilo
Product chamilo
Published 2021-04-30
Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H