CVE-2025-34335: Audiocodes Fax Server command injection (CVSS 8.8)

Description

AudioCodes Fax Server and Auto-Attendant IVR appliances versions up to and including 2.6.23 expose an authenticated command injection vulnerability in the license activation workflow handled by AudioCodes_files/ActivateLicense.php. When a license file is uploaded, the application derives a new filename by combining a generated base name with the attacker-controlled extension portion of the original upload name, then constructs a command line for fax_server_lic_cmdline.exe that includes this path. The extension value is incorporated into the command string without input validation, escaping, or proper argument quotation before being passed to exec(). An authenticated user with access to the license upload interface can supply a specially crafted filename whose extension injects additional shell metacharacters, causing arbitrary commands to be executed as NT AUTHORITY\\SYSTEM.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredLow

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Audiocodes Fax Server≤ 2.6.23

Audiocodes Interactive Voice Response< 2.6.23

Remediation

Fixed in

Audiocodes Interactive Voice Response≥ 2.6.23

References

https://pierrekim.github.io/advisories/2025-audiocodes-fax-ivr.txtExploitThird Party Advisory
https://pierrekim.github.io/blog/2025-11-20-audiocodes-fax-ivr-8-vulnerabilities.htmlExploitThird Party Advisory
https://www.audiocodes.com/media/g1in2u2o/0548-product-notice-end-of-service-for-audiocodes-auto-attendant-ivr-solution.pdfProduct
https://www.vulncheck.com/advisories/audiocodes-fax-ivr-appliance-authenticated-command-injection-via-activatelicenseThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-34335 being actively exploited?

CVE-2025-34335 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 2.82%.

How severe is CVE-2025-34335?

CVE-2025-34335 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 2.82% probability of exploitation.

Which products are affected by CVE-2025-34335?

Affected products include Audiocodes Fax Server, Audiocodes Interactive Voice Response.

How do I fix CVE-2025-34335?

Upgrade affected software to a fixed version, for example Audiocodes Interactive Voice Response 2.6.23 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-34335 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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