HIGH CVSS 7.5
Published: 2020-12-09

CVE-2020-29656

asus rt-ac88u_firmware Security Advisory (CVE-2020-29656)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2020-29656?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2020-29656 impacting asus rt-ac88u_firmware. Evaluated with CVSS Base Score of 7.5 (HIGH).

Original NVD Description

Source: NIST NVD
An information disclosure vulnerability exists in RT-AC88U Download Master before 3.1.0.108. A direct access to /downloadmaster/dm_apply.cgi?action_mode=initial&download_type=General&special_cgi=get_language makes it possible to reach "unknown functionality" in a "known to be easy" manner via an unspecified "public exploit."

📊 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
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 asus / rt-ac88u_firmware
Affected Versions *
Weakness Enumeration CWE-425

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-2020-29656 impacting asus rt-ac88u_firmware.

⚡ Nuclei Detection Template (YAML) cve-2020-29656.yaml
id: cve-2020-29656

info:
  name: asus rt-ac88u_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2020-29656 affecting asus rt-ac88u_firmware.
    Evaluation: An information disclosure vulnerability exists in RT-AC88U Download Master before 3.1.0.108. A direct access to /downloadmaster/dm_apply.cgi?action_mo...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2020-29656
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 7.5
    cve-id: CVE-2020-29656
    cwe-id: CWE-425
  tags: cve,cve-2020-29656,asus,rt-ac88u_firmware,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "rt-ac88u_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2020-29656.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2020-29656
# Target: asus rt-ac88u_firmware | CVSS: 7.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2020-29656 (asus rt-ac88u_firmware)...")
    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 asus rt-ac88u_firmware 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-2020-29656.sh
# Recommended Remediation & Patching Commands for CVE-2020-29656
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install rt-ac88u_firmware 2>/dev/null || \
sudo dnf upgrade rt-ac88u_firmware 2>/dev/null || \
sudo yum update rt-ac88u_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i rt-ac88u_firmware 2>/dev/null || rpm -qa | grep -i rt-ac88u_firmware

# 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-2020-29656 in asus rt-ac88u_firmware?

Review vendor-specific security notices and update asus rt-ac88u_firmware 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-2020-29656?

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-2020-29656?

CVE-2020-29656 is classified with a CVSS 3.1 Base Score of 7.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.5
HIGH SEVERITY
CVE ID CVE-2020-29656
Weakness CWE-425
Vendor asus
Product rt-ac88u_firmware
Published 2020-12-09
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N