High · published October 15, 2025
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.
| Product | Versions | Fixed in |
|---|---|---|
| cisco/desk_phone_9871_firmware | ≥ 3.0\(1\), ≤ 3.2\(1\) | — |
| cisco/desk_phone_9841_firmware | ≥ 3.0\(1\), ≤ 3.2\(1\) | — |
| cisco/desk_phone_9851_firmware | ≥ 3.0\(1\), ≤ 3.2\(1\) | — |
| cisco/desk_phone_9861_firmware | ≥ 3.0\(1\), ≤ 3.2\(1\) | — |
| cisco/ip_phone_8865_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8865_firmware | all versions | — |
| cisco/ip_phone_8865_firmware | all versions | — |
| cisco/ip_phone_7811_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_7811_firmware | all versions | — |
| cisco/ip_phone_7811_firmware | all versions | — |
| cisco/ip_phone_7821_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_7821_firmware | all versions | — |
| cisco/ip_phone_7821_firmware | all versions | — |
| cisco/ip_phone_7841_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_7841_firmware | all versions | — |
| cisco/ip_phone_7841_firmware | all versions | — |
| cisco/ip_phone_7861_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_7861_firmware | all versions | — |
| cisco/ip_phone_7861_firmware | all versions | — |
| cisco/ip_phone_8811_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8811_firmware | all versions | — |
| cisco/ip_phone_8811_firmware | all versions | — |
| cisco/ip_phone_8832_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8832_firmware | all versions | — |
| cisco/ip_phone_8832_firmware | all versions | — |
| cisco/ip_phone_8841_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8841_firmware | all versions | — |
| cisco/ip_phone_8841_firmware | all versions | — |
| cisco/ip_phone_8845_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8845_firmware | all versions | — |
| cisco/ip_phone_8845_firmware | all versions | — |
| cisco/ip_phone_8851_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8851_firmware | all versions | — |
| cisco/ip_phone_8851_firmware | all versions | — |
| cisco/ip_phone_8861_firmware | < 14.3\(1\) | 14.3\(1\) |
| cisco/ip_phone_8861_firmware | all versions | — |
| cisco/ip_phone_8861_firmware | all versions | — |
| cisco/video_phone_8875_firmware | < 2.3\(1\) | 2.3\(1\) |
| cisco/video_phone_8875_firmware | ≥ 3.0\(1\), ≤ 3.2\(1\) | — |
| cisco/video_phone_8875_firmware | all versions | — |
| cisco/video_phone_8875_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | < 11.0\(1\) | 11.0\(1\) |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |
| cisco/ip_phone_8821_firmware | all versions | — |