CVE-2025-34334 — AudioCodes Fax/IVR Appliance <= 2.6.23 Authenticated Command Injection via TestFax.php & LPE
AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 are vulnerable to an authenticated command injection in the fax test functionality implemented by AudioCodes_files/TestFax.php. When a fax "send" test is requested, the application builds a faxsender command line using attacker-supplied parameters and passes it to GlobalUtils::RunBatchFile without proper validation or shell-argument sanitization. The resulting batch file is written into a temporary run directory and then executed via a backend service that runs as NT AUTHORITY\\SYSTEM. An authenticated attacker with access to the fax test interface can craft parameter values that inject additional shell commands into the generated batch file, leading to arbitrary command execution with SYSTEM privileges. In addition, because the generated batch files reside in a location with overly permissive file system permissions, a local low-privilege user on the server can modify pending batch files to achieve the same elevation.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 3.4% (30-day exploitation probability)+13
- Technical severity (high)+6
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
CISA SSVC assessment CISA
Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Audiocodes AudioCodes Fax/IVR Appliance, Audiocodes Fax Server, Audiocodes Interactive Voice Response).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes matching the vulnerability class (injection), errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Audiocodes | AudioCodes Fax/IVR Appliance | ≤ 2.6.23 | Vulnerable | CVE Program (cve.org) e CISA ADP |
| Audiocodes | Fax Server | ≤ 2.6.23 | Vulnerable | NIST National Vulnerability Database |
| Audiocodes | Interactive Voice Response | ≤ 2.6.23 | Vulnerable | NIST National Vulnerability Database |
Attack characteristics
The CVSS vector, decoded. It describes the attack, not your exposure to it.
Every base score collected
Sources score independently and may disagree; each row says who scored it and under which version.
| Score | Version | Severity | Expl. | Impact | Scored by |
|---|---|---|---|---|---|
| 8.7 | CVSS 4.0 | High | — | — | disclosure@vulncheck.com via NIST National Vulnerability Database |
| 8.7 | CVSS 4.0 | High | — | — | VulnCheck via CVE Program (cve.org) e CISA ADP |
| 8.8 | CVSS 3.1 | High | 2.8 | 5.9 | nvd@nist.gov via NIST National Vulnerability Database |
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H (score shown at the top: nvd@nist.gov) Weakness MITRE
Weakness class according to MITRE’s CWE catalog.
EPSS over time FIRST
Oct 13, 2026 → Oct 14, 2026 · 2 reading(s) · max 3.44%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
- Look for parameters with command/query metacharacters and unexpected child processes of the service.
Timeline
What happened to this CVE, newest first.
- 2026
- Affected products added · audiocodes limited/audiocodes fax/ivr appliance
- SSVC assessment updated
- Record published
- CVSS changed · 8.8
- Source status changed · → Analyzed
- Record created in this database
- 2025
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
4 on the record
- www.audiocodes.com/media/g1in2u2o/0548-product-notice-end-of-service-for-audiocodes-auto
- pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txt
- pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.html
- www.vulncheck.com/advisories/audiocodes-fax-ivr-appliance-authenticated-command-injecti
Elsewhere on this site
Related CVEs (same products)
- High CVE-2025-34332 AudioCodes Fax/IVR Appliance <= 2.6.23 Insecure Service Control Scripts LPE Nov 19, 2025
- High CVE-2025-34333 AudioCodes Fax/IVR Appliance <= 2.6.23 World-Writable Webroot LPE Nov 19, 2025
- High CVE-2025-34335 AudioCodes Fax/IVR Appliance <= 2.6.23 Authenticated Command Injection via ActivateLicense.php Nov 19, 2025
- Critical CVE-2025-34328 AudioCodes Fax/IVR Appliance <= 2.6.23 Unauthenticated File Upload RCE via ajaxScript.php Nov 19, 2025
- Critical CVE-2025-34329 AudioCodes Fax/IVR Appliance <= 2.6.23 Unauthenticated Backup Upload RCE via ajaxBackupUploadFile.php Nov 19, 2025
- Medium CVE-2025-34330 AudioCodes Fax/IVR Appliance <= 2.6.23 Unauthenticated Prompt File Upload via ajaxPromptUploadFile.php Nov 19, 2025
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 fixed version, patch or mitigation documented.
- 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.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-34334 is "AudioCodes Fax/IVR Appliance <= 2.6.23 Authenticated Command Injection via TestFax.php & LPE", rated High. It affects AudioCodes Fax/IVR Appliance (Audiocodes); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 8.8 describes technical severity. EPSS 3.44% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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