XSS in Cisco Session Initiation Protocol (Sip) Software
CVE-2025-20351
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.003 (18.7th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Cisco Session Initiation Protocol (Sip) Software — versions 12.1(1)SR1, 11.5(1), 10.3(2)
- Cisco Desk_phone_9841
- Cisco Desk_phone_9841_firmware
- Cisco Desk_phone_9851
- Cisco Desk_phone_9851_firmware
- Cisco Desk_phone_9861
- Cisco Desk_phone_9861_firmware
- Cisco Desk_phone_9871
- Cisco Desk_phone_9871_firmware
- Cisco Ip_phone_7811
Weakness classification (CWE)
Public proof-of-concept exploits
References
- psirt@cisco.com (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-20351?
- CVE-2025-20351 is a medium-severity vulnerability in Cisco Session Initiation Protocol (Sip) Software, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-10-15.
- How severe is CVE-2025-20351?
- Medium severity. CVSS v3 base score is 6.1 out of 10.
- Is CVE-2025-20351 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.