HIGH CVSS 7.5
Published: 2020-11-26

CVE-2020-29043

bigbluebutton bigbluebutton Security Advisory (CVE-2020-29043)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-29043 impacting bigbluebutton bigbluebutton. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD
An issue was discovered in BigBlueButton through 2.2.29. When at attacker is able to view an account_activations/edit?token= URI, the attacker can create an approved user account associated with an email address that has an arbitrary domain name.

📊 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
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
None (C:N)
No data confidentiality impact
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product bigbluebutton / bigbluebutton
Affected Versions *
Weakness Enumeration CWE-200

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-2020-29043 impacting bigbluebutton bigbluebutton.

⚡ Nuclei Detection Template (YAML) cve-2020-29043.yaml
id: cve-2020-29043

info:
  name: bigbluebutton bigbluebutton - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2020-29043 affecting bigbluebutton bigbluebutton.
    Evaluation: An issue was discovered in BigBlueButton through 2.2.29. When at attacker is able to view an account_activations/edit?token= URI, the attacker can cre...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-29043
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
    cvss-score: 7.5
    cve-id: CVE-2020-29043
    cwe-id: CWE-200
  tags: cve,cve-2020-29043,bigbluebutton,bigbluebutton,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "bigbluebutton"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-29043.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-29043
# Target: bigbluebutton bigbluebutton | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-29043 (bigbluebutton bigbluebutton)...")
    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 bigbluebutton bigbluebutton 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-2020-29043.sh
# Recommended Remediation & Patching Commands for CVE-2020-29043
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install bigbluebutton 2>/dev/null || \
sudo dnf upgrade bigbluebutton 2>/dev/null || \
sudo yum update bigbluebutton

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

# 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-2020-29043 in bigbluebutton bigbluebutton?

Review vendor-specific security notices and update bigbluebutton bigbluebutton 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-2020-29043?

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-2020-29043?

CVE-2020-29043 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.5
HIGH SEVERITY
CVE ID CVE-2020-29043
Weakness CWE-200
Vendor bigbluebutton
Product bigbluebutton
Published 2020-11-26
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N