CVE-2025-34328: Audiocodes Fax Server

Critical severity, CVSS 9.8. EPSS: 0.7% chance of exploitation in the next 30 days.

AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 include a web administration component (F2MAdmin) that exposes an unauthenticated script-management endpoint at AudioCodes_files/utils/IVR/diagram/ajaxScript.php. The saveScript action writes attacker-supplied data directly to a server-side file path under the privileges of the web service account, which runs as NT AUTHORITY\\SYSTEM on Windows deployments. A remote, unauthenticated attacker can write arbitrary files into the product’s web-accessible directory structure and subsequently execute them.

Affected products

• Audiocodes Fax Server: up to and including 2.6.23
• Audiocodes Interactive Voice Response: up to and including 2.6.23

Published 2025-11-19. Last modified 2026-06-17.