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
Published · last modified .
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.
EPSS exploit prediction
EPSS: 0.007 (51.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 52nd percentile — 51.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: 0.000
Affected products
Weakness classification (CWE)
References
- www.audiocodes.com/media/g1in2u2o/0548-product-notice-end-of-service-for-audioc… (Product, vendor-advisory, patch, mitigation)
- pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.html (Exploit, technical-description, Third Party Advisory, exploit)
- pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txt (Exploit, technical-description, Third Party Advisory, exploit)
- www.vulncheck.com/advisories/audiocodes-fax-ivr-appliance-unauthenticated-file-… (Third Party Advisory, third-party-advisory)
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.