HIGH CVSS 8.1
Published: 2021-03-03

CVE-2021-22863

github github Security Advisory (CVE-2021-22863)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2021-22863?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-22863 impacting github github. Evaluated with CVSS Base Score of 8.1 (HIGH).

Original NVD Description

Source: NIST NVD
An improper access control vulnerability was identified in the GitHub Enterprise Server GraphQL API that allowed authenticated users of the instance to modify the maintainer collaboration permission of a pull request without proper authorization. By exploiting this vulnerability, an attacker would be able to gain access to head branches of pull requests opened on repositories of which they are a maintainer. Forking is disabled by default for organization owned private repositories and would prevent this vulnerability. Additionally, branch protections such as required pull request reviews or status checks would prevent unauthorized commits from being merged without further review or validation. This vulnerability affected all versions of GitHub Enterprise Server since 2.12.22 and was fixed in versions 2.20.24, 2.21.15, 2.22.7 and 3.0.1. This vulnerability was reported via the GitHub Bug Bounty program.

📊 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
Low (PR:L)
Standard user access 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
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product github / github
Affected Versions *
Weakness Enumeration CWE-285

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-2021-22863 impacting github github.

⚡ Nuclei Detection Template (YAML) cve-2021-22863.yaml
id: cve-2021-22863

info:
  name: github github - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2021-22863 affecting github github.
    Evaluation: An improper access control vulnerability was identified in the GitHub Enterprise Server GraphQL API that allowed authenticated users of the instance t...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-22863
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
    cvss-score: 8.1
    cve-id: CVE-2021-22863
    cwe-id: CWE-285
  tags: cve,cve-2021-22863,github,github,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "github"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-22863.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-22863
# Target: github github | CVSS: 8.1 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-22863 (github github)...")
    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 github github 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-2021-22863.sh
# Recommended Remediation & Patching Commands for CVE-2021-22863
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install github 2>/dev/null || \
sudo dnf upgrade github 2>/dev/null || \
sudo yum update github

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

# 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-2021-22863 in github github?

Review vendor-specific security notices and update github github 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-2021-22863?

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-2021-22863?

CVE-2021-22863 is classified with a CVSS 3.1 Base Score of 8.1 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.1
HIGH SEVERITY
CVE ID CVE-2021-22863
Weakness CWE-285
Vendor github
Product github
Published 2021-03-03
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N