CVE-2025-20351 Cross-site scripting in Cisco Session Initiation Protocol (SIP) Software

Medium 6.1 Published Updated

An unauthenticated remote attacker can execute arbitrary script code or access sensitive information via XSS in the web UI of Cisco IP phones.

Exploited in the wild
Not known
Login needed
Not needed
Attackable
Over the internet
Victim action needed
A user has to click or open something
Fix
None listed

What is CVE-2025-20351?

CVE-2025-20351 is a medium-severity cross-site scripting vulnerability in Cisco Session Initiation Protocol (SIP) Software, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

A vulnerability in the web UI of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800 Series, and Cisco Video Phone 8875 running Cisco SIP Software could allow an unauthenticated, remote attacker to conduct XSS attacks against a user of the web UI. This vulnerability exists because the web UI of an affected device does not sufficiently validate user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive, browser-based information. Note: To exploit this vulnerability, the phone must be registered to Cisco Unified Communications Manager and have Web Access enabled. Web Access is disabled by default.

Weakness: CWE-79

Which versions are affected by CVE-2025-20351?

It affects 17 products.

Products include Cisco Desk Phone 9841 Firmware, Cisco Desk Phone 9851 Firmware, Cisco Desk Phone 9861 Firmware, Cisco Desk Phone 9871 Firmware, Cisco Ip Phone 7811 Firmware, Cisco Ip Phone 7821 Firmware and 11 more.

How do I fix CVE-2025-20351?

No fix has been published for CVE-2025-20351 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2025-20351 being exploited?

There is no known exploitation of CVE-2025-20351 in the wild and no public exploit code.

Sources

Also known as GHSA-q352-cxfj-h569.

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