CVE-2025-34328: Audiocodes Fax Server unrestricted file upload (CVSS 9.8)

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/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

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

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-unauthenticated-file-upload-rce-via-ajaxscriptThird Party Advisory

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

Frequently asked

Is CVE-2025-34328 being actively exploited?

CVE-2025-34328 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.71%.

How severe is CVE-2025-34328?

CVE-2025-34328 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.71% probability of exploitation.

Which products are affected by CVE-2025-34328?

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

How do I fix CVE-2025-34328?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-34328 against the real software inventory on every managed device, as each hourly inventory arrives. 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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