HIGH CVSS 8.8
Published: 2025-11-19

CVE-2025-34335

audiocodes fax_server Security Advisory (CVE-2025-34335)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2025-34335 impacting audiocodes fax_server. Evaluated with CVSS Base Score of 8.8 (HIGH).

Original NVD Description

Source: NIST NVD
AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in the license activation workflow handled by AudioCodes_files/ActivateLicense.php. When a license file is uploaded, the application derives a new filename by combining a generated base name with the attacker-controlled extension portion of the original upload name, then constructs a command line for fax_server_lic_cmdline.exe that includes this path. The extension value is incorporated into the command string without input validation, escaping, or proper argument quotation before being passed to exec(). An authenticated user with access to the license upload interface can supply a specially crafted filename whose extension injects additional shell metacharacters, causing arbitrary commands to be executed as NT AUTHORITY\\SYSTEM.

📊 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 audiocodes / fax_server
Affected Versions *
Weakness Enumeration CWE-78

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-2025-34335 impacting audiocodes fax_server.

⚡ Nuclei Detection Template (YAML) cve-2025-34335.yaml
id: cve-2025-34335

info:
  name: audiocodes fax_server - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2025-34335 affecting audiocodes fax_server.
    Evaluation: AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2025-34335
  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-2025-34335
    cwe-id: CWE-78
  tags: cve,cve-2025-34335,audiocodes,fax_server,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "fax_server"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2025-34335.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2025-34335
# Target: audiocodes fax_server | 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-2025-34335 (audiocodes fax_server)...")
    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 audiocodes fax_server 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-2025-34335.sh
# Recommended Remediation & Patching Commands for CVE-2025-34335
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install fax_server 2>/dev/null || \
sudo dnf upgrade fax_server 2>/dev/null || \
sudo yum update fax_server

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

# 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-2025-34335 in audiocodes fax_server?

Review vendor-specific security notices and update audiocodes fax_server 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-2025-34335?

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-2025-34335?

CVE-2025-34335 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-2025-34335
Weakness CWE-78
Vendor audiocodes
Product fax_server
Published 2025-11-19
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H