HIGH CVSS 7.3
Published: 2022-09-12

CVE-2022-39200

matrix dendrite Security Advisory (CVE-2022-39200)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2022-39200 impacting matrix dendrite. Evaluated with CVSS Base Score of 7.3 (HIGH).

Original NVD Description

Source: NIST NVD
Dendrite is a Matrix homeserver written in Go. In affected versions events retrieved from a remote homeserver using the `/get_missing_events` path did not have their signatures verified correctly. This could potentially allow a remote homeserver to provide invalid/modified events to Dendrite via this endpoint. Note that this does not apply to events retrieved through other endpoints (e.g. `/event`, `/state`) as they have been correctly verified. Homeservers that have federation disabled are not vulnerable. The problem has been fixed in Dendrite 0.9.8. Users are advised to upgrade. There are no known workarounds for this issue.

📊 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
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product matrix / dendrite
Affected Versions *
Weakness Enumeration CWE-347

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-2022-39200 impacting matrix dendrite.

⚡ Nuclei Detection Template (YAML) cve-2022-39200.yaml
id: cve-2022-39200

info:
  name: matrix dendrite - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2022-39200 affecting matrix dendrite.
    Evaluation: Dendrite is a Matrix homeserver written in Go. In affected versions events retrieved from a remote homeserver using the `/get_missing_events` path did...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2022-39200
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
    cvss-score: 7.3
    cve-id: CVE-2022-39200
    cwe-id: CWE-347
  tags: cve,cve-2022-39200,matrix,dendrite,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "dendrite"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2022-39200.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2022-39200
# Target: matrix dendrite | CVSS: 7.3 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2022-39200 (matrix dendrite)...")
    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 matrix dendrite 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-2022-39200.sh
# Recommended Remediation & Patching Commands for CVE-2022-39200
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install dendrite 2>/dev/null || \
sudo dnf upgrade dendrite 2>/dev/null || \
sudo yum update dendrite

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

# 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-2022-39200 in matrix dendrite?

Review vendor-specific security notices and update matrix dendrite 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-2022-39200?

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-2022-39200?

CVE-2022-39200 is classified with a CVSS 3.1 Base Score of 7.3 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.3
HIGH SEVERITY
CVE ID CVE-2022-39200
Weakness CWE-347
Vendor matrix
Product dendrite
Published 2022-09-12
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L