CVE-2025-20351
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk19th percentile - higher than 19% of all known CVEs
Summary
A vulnerability in the web UI of Cisco Desk Phone 9800 Series, IP Phone 7800/8800 Series, and Video Phone 8875 running Cisco SIP Software allows an unauthenticated, remote attacker to conduct XSS attacks against a user of the web UI. The issue exists due to insufficient validation of user-supplied input. Exploitation requires the user to click a crafted link, and the phone must be registered to Cisco Unified Communications Manager with Web Access enabled (disabled by default).
Risk Assessment
Successful exploitation could allow arbitrary script execution in the context of the interface or access sensitive browser-based information, potentially leading to session hijacking or data theft.
Recommendation
Upgrade the SIP software to the latest version and disable Web Access if not needed. Also educate users to avoid clicking suspicious links.
Other vulnerabilities in Cisco SIP Software
See all- CVE-2026-20281High
A vulnerability in Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 running SIP Software allows an unauthenticated, remote attacker to cause a DoS condition. It is due to improper memory management when processing HTTP packets, and exploitation involves sending a continuous stream of crafted HTTP packets.
- CVE-2025-20350High
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 cause a DoS condition on an affected device. This is due to a buffer overflow when processing HTTP packets. An attacker could exploit this by sending crafted HTTP input, causing the device to reload. To exploit, the phone must be registered to Cisco Unified Communications Manager and have Web Access enabled (disabled by default).
Original NVD description (English source)
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 data from NVD (NIST) · CISA KEV · EPSS