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

Published Oct 15, 2025
·
Updated

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 Software

89 affected components
Cisco Desk Phone 9800 Series
Cisco IP Phone 7800 Series
Cisco IP Phone 8800 Series
Cisco Video Phone 8875
All of the following
Cisco Desk Phone 9871 Firmware>=3.0\(1\)<=3.2\(1\)
Cisco Desk Phone 9871
All of the following
Cisco Desk Phone 9841 Firmware>=3.0\(1\)<=3.2\(1\)
Cisco Desk Phone 9841
All of the following
Cisco Desk Phone 9851 Firmware>=3.0\(1\)<=3.2\(1\)
Cisco Desk Phone 9851
All of the following
Cisco Desk Phone 9861 Firmware>=3.0\(1\)<=3.2\(1\)
Cisco Desk Phone 9861
All of the following
Any of the following
Cisco Ip Phone 8865 Firmware<14.3\(1\)
Cisco Ip Phone 8865 Firmware=14.3\(1\)
Cisco Ip Phone 8865 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8865
All of the following
Any of the following
Cisco Ip Phone 7811 Firmware<14.3\(1\)
Cisco Ip Phone 7811 Firmware=14.3\(1\)
Cisco Ip Phone 7811 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 7811
All of the following
Any of the following
Cisco Ip Phone 7821 Firmware<14.3\(1\)
Cisco Ip Phone 7821 Firmware=14.3\(1\)
Cisco Ip Phone 7821 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 7821
All of the following
Any of the following
Cisco Ip Phone 7841 Firmware<14.3\(1\)
Cisco Ip Phone 7841 Firmware=14.3\(1\)
Cisco Ip Phone 7841 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 7841
All of the following
Any of the following
Cisco Ip Phone 7861 Firmware<14.3\(1\)
Cisco Ip Phone 7861 Firmware=14.3\(1\)
Cisco Ip Phone 7861 Firmware=14.3\(1\)-sr1
Cisco IP Phone 7861
All of the following
Any of the following
Cisco Ip Phone 8811 Firmware<14.3\(1\)
Cisco Ip Phone 8811 Firmware=14.3\(1\)
Cisco Ip Phone 8811 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8811
All of the following
Any of the following
Cisco Ip Phone 8832 Firmware<14.3\(1\)
Cisco Ip Phone 8832 Firmware=14.3\(1\)
Cisco Ip Phone 8832 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8832
All of the following
Any of the following
Cisco Ip Phone 8841 Firmware<14.3\(1\)
Cisco Ip Phone 8841 Firmware=14.3\(1\)
Cisco Ip Phone 8841 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8841
All of the following
Any of the following
Cisco Ip Phone 8845 Firmware<14.3\(1\)
Cisco Ip Phone 8845 Firmware=14.3\(1\)
Cisco Ip Phone 8845 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8845
All of the following
Any of the following
Cisco Ip Phone 8851 Firmware<14.3\(1\)
Cisco Ip Phone 8851 Firmware=14.3\(1\)
Cisco Ip Phone 8851 Firmware=14.3\(1\)-sr1
Cisco IP Phone 8851
All of the following
Any of the following
Cisco Ip Phone 8861 Firmware<14.3\(1\)
Cisco Ip Phone 8861 Firmware=14.3\(1\)
Cisco Ip Phone 8861 Firmware=14.3\(1\)-sr1
Cisco Ip Phone 8861
All of the following
Any of the following
Cisco Video Phone 8875 Firmware<2.3\(1\)
Cisco Video Phone 8875 Firmware>=3.0\(1\)<=3.2\(1\)
Cisco Video Phone 8875 Firmware=2.3\(1\)
Cisco Video Phone 8875 Firmware=2.3\(1\)-sr1
Cisco Video Phone 8875
All of the following
Any of the following
Cisco Ip Phone 8821 Firmware<11.0\(1\)
Cisco Ip Phone 8821 Firmware=11.0\(0.7\)-mpp
Cisco Ip Phone 8821 Firmware=11.0\(1\)
Cisco Ip Phone 8821 Firmware=11.0\(2\)
Cisco Ip Phone 8821 Firmware=11.0\(2\)-sr1
Cisco Ip Phone 8821 Firmware=11.0\(2\)-sr2
Cisco Ip Phone 8821 Firmware=11.0\(3\)
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr1
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr2
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr3
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr4
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr5
Cisco Ip Phone 8821 Firmware=11.0\(3\)-sr6
Cisco Ip Phone 8821 Firmware=11.0\(4\)
Cisco Ip Phone 8821 Firmware=11.0\(4\)-sr1
Cisco Ip Phone 8821 Firmware=11.0\(4\)-sr2
Cisco Ip Phone 8821 Firmware=11.0\(4\)-sr3
Cisco Ip Phone 8821 Firmware=11.0\(5\)
Cisco Ip Phone 8821 Firmware=11.0\(5\)-sr1
Cisco Ip Phone 8821 Firmware=11.0\(5\)-sr2
Cisco Ip Phone 8821 Firmware=11.0\(5\)-sr3
Cisco Ip Phone 8821 Firmware=11.0\(6\)
Cisco Ip Phone 8821 Firmware=11.0\(6\)-sr1
Cisco Ip Phone 8821 Firmware=11.0\(6\)-sr2
Cisco Ip Phone 8821 Firmware=11.0\(6\)-sr4
Cisco Ip Phone 8821 Firmware=11.0\(6\)-sr5
Cisco Ip Phone 8821 Firmware=11.0\(6\)-sr6
Cisco IP Phone 8821

Event History

Oct 15, 2025
CVE Published
via MITRE·04:15 PM
Data Sourced
via MITRE·04:15 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·05:15 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2025-20350?

CVE-2025-20350 has been classified as a high severity vulnerability due to its potential to cause a denial of service condition.

2

How do I fix CVE-2025-20350?

To mitigate CVE-2025-20350, it is recommended to update the affected Cisco devices running the latest firmware provided by Cisco.

3

Which devices are affected by CVE-2025-20350?

CVE-2025-20350 affects Cisco Desk Phone 9800 Series, Cisco IP Phone 7800 Series, Cisco IP Phone 8800 Series, and Cisco Video Phone 8875.

4

What type of attack does CVE-2025-20350 enable?

CVE-2025-20350 allows an unauthenticated, remote attacker to execute a denial of service (DoS) attack on the affected devices.

5

Is authentication required to exploit CVE-2025-20350?

No, CVE-2025-20350 can be exploited by an unauthenticated attacker, which increases its risk factor.

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