CVE-2025-34329
CVE-2025-34329 — AudioCodes Fax/IVR Appliance <= 2.6.23 Unauthenticated Backup Upload RCE via ajaxBackupUploadFile.php
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.
Published Updated Sources: cvelistV5, VulnCheck
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the scoring sources call it.
Exploitation
Unreported
no source claims exploitation
EPSS
1%
chance of exploitation in 30 days
CVSS base
9.3
CRITICAL
CISA SSVC assessment
Three decision points CISA publishes for the CVEs it assesses · SSVC 2.0.3. A stakeholder decision, not a severity score.
Exploitation
None
none · proof-of-concept · active
Automatable
Yes
can an attacker script all four kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component
Affected scope
The catalog records vendors and products as separate lists, not pairs, so which product belongs to which vendor is not something this page can say.
Vendors (1)
Products (1)
Every base score collected
Sources score independently and disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Source |
|---|---|---|---|---|---|
| 9.3 | CVSS 4.0 | CRITICAL | — | — | cvelistV5 |
Weakness & attack patterns
- CWE-434
Attack patterns reported against this CVE. The ATT&CK techniques below are inferred from its weakness class.
- T1574.010Hijack Execution Flow: ServicesFile Permissions Weakness
Detection
Read off the CVSS vector and the weakness class. Starting points, not rules we have tested.
- Search application, proxy, and WAF logs for requests touching /ajaxBackupUploadFile.php.
References
4 on the record
- www.audiocodes.com/media/g1in2u2o/0548-product-notice-end-of-service-for-audiocodes-auto-attendant-ivr-solution.pdf
vendor-advisory, patch, mitigation
- pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.html
technical-description, exploit
- pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txt
technical-description, exploit
- www.vulncheck.com/advisories/audiocodes-fax-ivr-appliance-unauthenticated-backup-upload-rce-via-ajaxbackupuploadfile
third-party-advisory
Elsewhere on this site
- audiocodesevery CVE for this vendor
- CWE-434other pages naming this weakness
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.