HIGH CVSS 7.8
Published: 2025-04-22

CVE-2025-1731

zyxel uos Security Advisory (CVE-2025-1731)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2025-1731?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-1731 impacting zyxel uos. Evaluated with CVSS Base Score of 7.8 (HIGH).

Original NVD Description

Source: NIST NVD
An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1.31 could allow an authenticated local attacker with low privileges to gain access to the Linux shell and escalate their privileges by crafting malicious scripts or modifying system configurations with administrator-level access through a stolen token. Modifying the system configuration is only possible if the administrator has not logged out and the token remains valid.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Local (AV:L)
Requires local system execution permissions
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 zyxel / uos
Affected Versions *
Weakness Enumeration CWE-732

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-2025-1731 impacting zyxel uos.

⚡ Nuclei Detection Template (YAML) cve-2025-1731.yaml
id: cve-2025-1731

info:
  name: zyxel uos - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2025-1731 affecting zyxel uos.
    Evaluation: An incorrect permission assignment vulnerability in the PostgreSQL commands of the Zyxel USG FLEX H series uOS firmware versions from V1.20 through V1...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-1731
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 7.8
    cve-id: CVE-2025-1731
    cwe-id: CWE-732
  tags: cve,cve-2025-1731,zyxel,uos,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "uos"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-1731.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-1731
# Target: zyxel uos | CVSS: 7.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2025-1731 (zyxel uos)...")
    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 zyxel uos 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-2025-1731.sh
# Recommended Remediation & Patching Commands for CVE-2025-1731
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install uos 2>/dev/null || \
sudo dnf upgrade uos 2>/dev/null || \
sudo yum update uos

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

# 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-2025-1731 in zyxel uos?

Review vendor-specific security notices and update zyxel uos 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-2025-1731?

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-2025-1731?

CVE-2025-1731 is classified with a CVSS 3.1 Base Score of 7.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.8
HIGH SEVERITY
CVE ID CVE-2025-1731
Weakness CWE-732
Vendor zyxel
Product uos
Published 2025-04-22
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H