CVE-2025-20350
Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Firmware Denial of Service Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
7.5
Cisco Desk Phone 9800 Series, IP Phone 7800 and 8800 Series, and Video Phone 8875 with SIP Firmware Denial of Service Vulnerability
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.
- Record
CVE-2025-20350- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
EUVDEUVD-2025-34667
7.5
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.
- Record
EUVD-2025-34667- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-c6wg-233f-cjj6
7.5
A vulnerability in the web UI of Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 and 8800...
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.
- Record
GHSA-c6wg-233f-cjj6- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
NVD
7.5
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.
- Record
CVE-2025-20350- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-121
- Updated
- 2026-11-02
Affected products
- cisco session initiation protocol (sip) software
- 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
- cisco ip phone 7841 firmware
- cisco ip phone 7861 firmware
- cisco ip phone 8811 firmware
- cisco ip phone 8821 firmware
- cisco ip phone 8832 firmware
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-20350 is a high vulnerability (CVSS 7.5) in Cisco Session Initiation Protocol (sip) Software, published October 15, 2025. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.48%, the 41st percentile. No source names a fixed version.