Buffer overflow in Cisco Session Initiation Protocol (Sip) Software
CVE-2025-20350
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.
Vulnerability class: Buffer Overflow
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.005 (40.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 40.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.005 · change: 0.000
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
Frequently asked questions
- What is CVE-2025-20350?
- CVE-2025-20350 is a high-severity vulnerability in Cisco Session Initiation Protocol (Sip) Software, classified under Stack-based Buffer Overflow. CVSS score: 7.5/10. Published 2025-10-15.
- How severe is CVE-2025-20350?
- High severity. CVSS v3 base score is 7.5 out of 10.
- Is CVE-2025-20350 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.