HIGH CVSS 8.8
Published: 2022-08-25

CVE-2021-25642

apache hadoop Security Advisory (CVE-2021-25642)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-25642 impacting apache hadoop. Evaluated with CVSS Base Score of 8.8 (HIGH).

Original NVD Description

Source: NIST NVD
ZKConfigurationStore which is optionally used by CapacityScheduler of Apache Hadoop YARN deserializes data obtained from ZooKeeper without validation. An attacker having access to ZooKeeper can run arbitrary commands as YARN user by exploiting this. Users should upgrade to Apache Hadoop 2.10.2, 3.2.4, 3.3.4 or later (containing YARN-11126) if ZKConfigurationStore is used.

📊 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
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product apache / hadoop
Affected Versions *
Weakness Enumeration CWE-502

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-2021-25642 impacting apache hadoop.

⚡ Nuclei Detection Template (YAML) cve-2021-25642.yaml
id: cve-2021-25642

info:
  name: apache hadoop - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2021-25642 affecting apache hadoop.
    Evaluation: ZKConfigurationStore which is optionally used by CapacityScheduler of Apache Hadoop YARN deserializes data obtained from ZooKeeper without validation....
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-25642
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 8.8
    cve-id: CVE-2021-25642
    cwe-id: CWE-502
  tags: cve,cve-2021-25642,apache,hadoop,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "hadoop"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-25642.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-25642
# Target: apache hadoop | CVSS: 8.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-25642 (apache hadoop)...")
    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 apache hadoop 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-2021-25642.sh
# Recommended Remediation & Patching Commands for CVE-2021-25642
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install hadoop 2>/dev/null || \
sudo dnf upgrade hadoop 2>/dev/null || \
sudo yum update hadoop

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

# 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-2021-25642 in apache hadoop?

Review vendor-specific security notices and update apache hadoop 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-2021-25642?

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-2021-25642?

CVE-2021-25642 is classified with a CVSS 3.1 Base Score of 8.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.8
HIGH SEVERITY
CVE ID CVE-2021-25642
Weakness CWE-502
Vendor apache
Product hadoop
Published 2022-08-25
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H