CRITICAL CVSS 9.0
Published: 2021-02-17

CVE-2021-23885

mcafee web_gateway Security Advisory (CVE-2021-23885)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-23885 impacting mcafee web_gateway. Evaluated with CVSS Base Score of 9.0 (CRITICAL).

Original NVD Description

Source: NIST NVD
Privilege escalation vulnerability in McAfee Web Gateway (MWG) prior to 9.2.8 allows an authenticated user to gain elevated privileges through the User Interface and execute commands on the appliance via incorrect improper neutralization of user input in the troubleshooting page.

📊 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
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
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 mcafee / web_gateway
Affected Versions *
Weakness Enumeration CWE-269

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-2021-23885 impacting mcafee web_gateway.

⚡ Nuclei Detection Template (YAML) cve-2021-23885.yaml
id: cve-2021-23885

info:
  name: mcafee web_gateway - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2021-23885 affecting mcafee web_gateway.
    Evaluation: Privilege escalation vulnerability in McAfee Web Gateway (MWG) prior to 9.2.8 allows an authenticated user to gain elevated privileges through the Use...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-23885
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
    cvss-score: 9.0
    cve-id: CVE-2021-23885
    cwe-id: CWE-269
  tags: cve,cve-2021-23885,mcafee,web_gateway,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "web_gateway"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-23885.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-23885
# Target: mcafee web_gateway | CVSS: 9.0 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-23885 (mcafee web_gateway)...")
    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 mcafee web_gateway 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-2021-23885.sh
# Recommended Remediation & Patching Commands for CVE-2021-23885
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install web_gateway 2>/dev/null || \
sudo dnf upgrade web_gateway 2>/dev/null || \
sudo yum update web_gateway

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

# 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
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Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2021-23885 in mcafee web_gateway?

Review vendor-specific security notices and update mcafee web_gateway 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-2021-23885?

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-2021-23885?

CVE-2021-23885 is classified with a CVSS 3.1 Base Score of 9.0 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
9.0
CRITICAL SEVERITY
CVE ID CVE-2021-23885
Weakness CWE-269
Vendor mcafee
Product web_gateway
Published 2021-02-17
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H