Arbitrary file upload in Audiocodes Fax Server

CVE-2025-34328

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.

Vulnerability class: Unrestricted File Upload

EPSS: 0.007 (49.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-34328?
CVE-2025-34328 is a critical-severity vulnerability in Audiocodes Fax Server, classified under Unrestricted Upload of File with Dangerous Type. CVSS score: 9.8/10. Published 2025-11-19.
How severe is CVE-2025-34328?
Critical severity. CVSS v3 base score is 9.8 out of 10.