Vulnerability · Published Nov 19, 2025 · Assigned by VulnCheck
CVE-2025-34329AudioCodes Fax/IVR Appliance <= 2.6.23 Unauthenticated Backup Upload RCE via ajaxBackupUploadFile.php
Critical 9.3
In plain English
A critical-severity unrestricted file upload in AudioCodes Fax/IVR Appliance from AudioCodes Limited. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.2% (higher than 68% of all known vulnerabilities).
Official description
AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an unauthenticated backup upload endpoint at AudioCodes_files/ajaxBackupUploadFile.php in the F2MAdmin web interface. The script derives a backup folder path from application configuration, creates the directory if it does not exist, and then moves an uploaded file to that location using the attacker-controlled filename, without any authentication, authorization, or file-type validation. On default Windows deployments where the backup directory resolves to the system drive, a remote attacker can upload web server or interpreter configuration files that cause a log file or other server-controlled resource to be treated as executable code. This allows subsequent HTTP requests to trigger arbitrary command execution under the web server account, which runs as NT AUTHORITY\\SYSTEM.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| AudioCodes Limited | AudioCodes Fax/IVR Appliance | 0 – through 2.6.23 |
Weakness: CWE-434 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
References
- https://www.audiocodes.com/media/g1in2u2o/0548-product-notice-end-of-service-for-audiocodes-auto-attendant-ivr-solution.pdf vendor-advisory, patch, mitigation
- https://pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.html technical-description, exploit
- https://pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txt technical-description, exploit
- https://www.vulncheck.com/advisories/audiocodes-fax-ivr-appliance-unauthenticated-backup-upload-rce-via-ajaxbackupuploadfile third-party-advisory