CVE-2025-20350 Memory corruption in Cisco Session Initiation Protocol (SIP) Software
Unauthenticated remote attackers can cause a denial of service on Cisco IP phones via crafted HTTP packets if Web Access is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2025-20350?
CVE-2025-20350 is a high-severity memory corruption vulnerability in Cisco Session Initiation Protocol (SIP) Software, published on 15 Oct 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
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 cause a DoS condition on an affected device. This vulnerability is due to a buffer overflow when an affected device processes HTTP packets. An attacker could exploit this vulnerability by sending crafted HTTP input to the device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. 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-121
Which versions are affected by CVE-2025-20350?
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-2025-20350?
No fix has been published for CVE-2025-20350 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-20350 being exploited?
There is no known exploitation of CVE-2025-20350 in the wild and no public exploit code.
Other vulnerabilities in Cisco Session Initiation Protocol (SIP) Software
- CVE-2025-20351 Cross-site scripting in Cisco Session Initiation Protocol (SIP) Software
- CVE-2025-20335 Missing authorization in Cisco Session Initiation Protocol (SIP) Software
- CVE-2025-20336 Information disclosure in Cisco Session Initiation Protocol (SIP) Software
- CVE-2024-20445 Cisco IP Phone 7800, 8800, and 9800 Series Information Disclosure Vulnerability
- CVE-2025-20158 Cisco Video Phone 8875 and Desk Phone 9800 Series Information Disclosure Vulnerability
Sources
Also known as GHSA-c6wg-233f-cjj6.