Fax ServerApplication · Audiocodes

CVE-2025-34331

HIGH · 7.5 CVSS v3.1 Published 2025-11-19
Fix available
A fix is available. Upgrade to after 2.6.23 or later.
See remediation →
84/100
Remediation priority · High
Public exploit Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 contain an unauthenticated file read vulnerability via the download.php script. The endpoint exposes a file download mechanism that lacks access control, allowing remote, unauthenticated users to request files stored on the appliance based solely on attacker-supplied path and filename parameters. While limited to specific file extensions permitted by the application logic, sensitive backup archives can be retrieved, exposing internal databases and credential hashes. Successful exploitation may lead to disclosure of administrative password hashes and other sensitive configuration data.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis
How this class of weakness works · CWE-306

A sensitive function is reachable with no authentication at all, so anyone who finds the endpoint can use it. These are routinely discovered by automated scanning. The fix is to require and enforce authentication on every privileged path, with no exceptions left open.

General guidance for the missing authentication class — the official description and references above are authoritative for this specific CVE. Want a bespoke review and a reviewed fix? Ask our team →

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Fax ServerApplication
Affected:<= 2.6.23
Interactive Voice ResponseApplication
Affected:<= 2.6.23

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
None
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to a release after 2.6.23
Recommended fix Moderate confidence

AudioCodes Fax Server and IVR version 2.6.24 or later (check www.audiocodes.com for the exact current stable release)

  1. 1. Identify the current installed version of AudioCodes Fax Server or Interactive Voice Response (IVR) by accessing the admin interface or checking the system information.
  2. 2. Navigate to the official AudioCodes support portal at www.audiocodes.com and locate the product downloads section for Fax Server and IVR appliances.
  3. 3. Download the latest stable version of the software. Based on the affected version (2.6.23), the fixed version should be 2.6.24 or later.
  4. 4. Before upgrading, perform a complete backup of the current system configuration, including database files and settings.
  5. 5. Apply the firmware/software upgrade following the vendor's documented upgrade procedure, typically found in the product administration guide.
  6. 6. After upgrading, verify that the download.php endpoint now requires authentication or has been secured.
  7. 7. Change all administrative passwords immediately after the upgrade, as the vulnerability may have been exploited to obtain password hashes.
Caveat Standard upgrade; review release notes for any configuration changes or migration requirements

Generated from the published advisory — verify against the referenced sources before acting.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-34331 in production — separate from our analysis above.

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What this is

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