--- id: CVE-2025-20350 title: >- 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 affe… summary: >- 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 affe… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-121 vendor: cisco product: desk_phone_9871_firmware affected: - 'desk_phone_9871_firmware >= 3.0\(1\), <= 3.2\(1\)' - 'desk_phone_9841_firmware >= 3.0\(1\), <= 3.2\(1\)' - 'desk_phone_9851_firmware >= 3.0\(1\), <= 3.2\(1\)' - 'desk_phone_9861_firmware >= 3.0\(1\), <= 3.2\(1\)' - ip_phone_8865_firmware < 14.3\(1\) - ip_phone_8865_firmware = 14.3(1) - ip_phone_7811_firmware < 14.3\(1\) - ip_phone_7811_firmware = 14.3(1) - ip_phone_7821_firmware < 14.3\(1\) - ip_phone_7821_firmware = 14.3(1) - ip_phone_7841_firmware < 14.3\(1\) - ip_phone_7841_firmware = 14.3(1) - ip_phone_7861_firmware < 14.3\(1\) - ip_phone_7861_firmware = 14.3(1) - ip_phone_8811_firmware < 14.3\(1\) - ip_phone_8811_firmware = 14.3(1) - ip_phone_8832_firmware < 14.3\(1\) - ip_phone_8832_firmware = 14.3(1) - ip_phone_8841_firmware < 14.3\(1\) - ip_phone_8841_firmware = 14.3(1) - ip_phone_8845_firmware < 14.3\(1\) - ip_phone_8845_firmware = 14.3(1) - ip_phone_8851_firmware < 14.3\(1\) - ip_phone_8851_firmware = 14.3(1) - ip_phone_8861_firmware < 14.3\(1\) - ip_phone_8861_firmware = 14.3(1) - video_phone_8875_firmware < 2.3\(1\) - 'video_phone_8875_firmware >= 3.0\(1\), <= 3.2\(1\)' - video_phone_8875_firmware = 2.3(1) - ip_phone_8821_firmware < 11.0\(1\) - ip_phone_8821_firmware = 11.0(0.7) - ip_phone_8821_firmware = 11.0(1) - ip_phone_8821_firmware = 11.0(2) - ip_phone_8821_firmware = 11.0(3) - ip_phone_8821_firmware = 11.0(4) - ip_phone_8821_firmware = 11.0(5) - ip_phone_8821_firmware = 11.0(6) patched: - ip_phone_8865_firmware 14.3\(1\) - ip_phone_7811_firmware 14.3\(1\) - ip_phone_7821_firmware 14.3\(1\) - ip_phone_7841_firmware 14.3\(1\) - ip_phone_7861_firmware 14.3\(1\) - ip_phone_8811_firmware 14.3\(1\) - ip_phone_8832_firmware 14.3\(1\) - ip_phone_8841_firmware 14.3\(1\) - ip_phone_8845_firmware 14.3\(1\) - ip_phone_8851_firmware 14.3\(1\) - ip_phone_8861_firmware 14.3\(1\) - video_phone_8875_firmware 2.3\(1\) - ip_phone_8821_firmware 11.0\(1\) published: '2025-10-15' updated: '2026-10-08' sourceUpdated: '2026-10-08T11:10:00.250' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-20350' references: - url: >- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-phone-dos-FPyjLV7A label: psirt@cisco.com tags: - nvd epss: 0.00482 epssPercentile: 0.39578 ingestedAt: '2026-10-08T11:31:27.441Z' --- ## Overview 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. ## Affected - `desk_phone_9871_firmware >= 3.0\(1\), <= 3.2\(1\)` - `desk_phone_9841_firmware >= 3.0\(1\), <= 3.2\(1\)` - `desk_phone_9851_firmware >= 3.0\(1\), <= 3.2\(1\)` - `desk_phone_9861_firmware >= 3.0\(1\), <= 3.2\(1\)` - `ip_phone_8865_firmware < 14.3\(1\)` - `ip_phone_8865_firmware = 14.3(1)` - `ip_phone_7811_firmware < 14.3\(1\)` - `ip_phone_7811_firmware = 14.3(1)` - `ip_phone_7821_firmware < 14.3\(1\)` - `ip_phone_7821_firmware = 14.3(1)` - `ip_phone_7841_firmware < 14.3\(1\)` - `ip_phone_7841_firmware = 14.3(1)` - `ip_phone_7861_firmware < 14.3\(1\)` - `ip_phone_7861_firmware = 14.3(1)` - `ip_phone_8811_firmware < 14.3\(1\)` - `ip_phone_8811_firmware = 14.3(1)` - `ip_phone_8832_firmware < 14.3\(1\)` - `ip_phone_8832_firmware = 14.3(1)` - `ip_phone_8841_firmware < 14.3\(1\)` - `ip_phone_8841_firmware = 14.3(1)` - `ip_phone_8845_firmware < 14.3\(1\)` - `ip_phone_8845_firmware = 14.3(1)` - `ip_phone_8851_firmware < 14.3\(1\)` - `ip_phone_8851_firmware = 14.3(1)` - `ip_phone_8861_firmware < 14.3\(1\)` - `ip_phone_8861_firmware = 14.3(1)` - `video_phone_8875_firmware < 2.3\(1\)` - `video_phone_8875_firmware >= 3.0\(1\), <= 3.2\(1\)` - `video_phone_8875_firmware = 2.3(1)` - `ip_phone_8821_firmware < 11.0\(1\)` - `ip_phone_8821_firmware = 11.0(0.7)` - `ip_phone_8821_firmware = 11.0(1)` - `ip_phone_8821_firmware = 11.0(2)` - `ip_phone_8821_firmware = 11.0(3)` - `ip_phone_8821_firmware = 11.0(4)` - `ip_phone_8821_firmware = 11.0(5)` - `ip_phone_8821_firmware = 11.0(6)` ## Remediation Upgrade past the affected range: - `ip_phone_8865_firmware 14.3\(1\)` - `ip_phone_7811_firmware 14.3\(1\)` - `ip_phone_7821_firmware 14.3\(1\)` - `ip_phone_7841_firmware 14.3\(1\)` - `ip_phone_7861_firmware 14.3\(1\)` - `ip_phone_8811_firmware 14.3\(1\)` - `ip_phone_8832_firmware 14.3\(1\)` - `ip_phone_8841_firmware 14.3\(1\)` - `ip_phone_8845_firmware 14.3\(1\)` - `ip_phone_8851_firmware 14.3\(1\)` - `ip_phone_8861_firmware 14.3\(1\)` - `video_phone_8875_firmware 2.3\(1\)` - `ip_phone_8821_firmware 11.0\(1\)`