MEDIUM CVSS 6.5
Published: 2021-03-03

CVE-2021-22862

github github Security Advisory (CVE-2021-22862)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-22862 impacting github github. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
An improper access control vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with the ability to fork a repository to disclose Actions secrets for the parent repository of the fork. This vulnerability existed due to a flaw that allowed the base reference of a pull request to be updated to point to an arbitrary SHA or another pull request outside of the fork repository. By establishing this incorrect reference in a PR, the restrictions that limit the Actions secrets sent a workflow from forks could be bypassed. This vulnerability affected GitHub Enterprise Server version 3.0.0, 3.0.0.rc2, and 3.0.0.rc1. 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
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product github / github
Affected Versions 3.0.0
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-2021-22862 impacting github github.

⚡ Nuclei Detection Template (YAML) cve-2021-22862.yaml
id: cve-2021-22862

info:
  name: github github - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2021-22862 affecting github github.
    Evaluation: An improper access control vulnerability was identified in GitHub Enterprise Server that allowed an authenticated user with the ability to fork a repo...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-22862
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 6.5
    cve-id: CVE-2021-22862
    cwe-id: CWE-285
  tags: cve,cve-2021-22862,github,github,medium

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-2021-22862.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-22862
# Target: github github | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-22862 (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 (3.0.0).")
        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-2021-22862.sh
# Recommended Remediation & Patching Commands for CVE-2021-22862
# 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.

🔗 Verified Technical References

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2021-22862 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-2021-22862?

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-2021-22862?

CVE-2021-22862 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2021-22862
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:N/A:N