CVE-2025-20350

HIGH
Published Oct 15, 2025 Modified Dec 4, 2025 CWE-121

Description

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.

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CVSS v3.1 Score

7.5
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-121 CWE-121

Affected Products

Vendor Product
cisco desk_phone_9871_firmware
cisco desk_phone_9871
cisco desk_phone_9841_firmware
cisco desk_phone_9841
cisco desk_phone_9851_firmware
cisco desk_phone_9851
cisco desk_phone_9861_firmware
cisco desk_phone_9861
cisco ip_phone_8865_firmware
cisco ip_phone_8865_firmware
cisco ip_phone_8865_firmware
cisco ip_phone_8865
cisco ip_phone_7811_firmware
cisco ip_phone_7811_firmware
cisco ip_phone_7811_firmware
cisco ip_phone_7811
cisco ip_phone_7821_firmware
cisco ip_phone_7821_firmware
cisco ip_phone_7821_firmware
cisco ip_phone_7821
cisco ip_phone_7841_firmware
cisco ip_phone_7841_firmware
cisco ip_phone_7841_firmware
cisco ip_phone_7841
cisco ip_phone_7861_firmware
cisco ip_phone_7861_firmware
cisco ip_phone_7861_firmware
cisco ip_phone_7861
cisco ip_phone_8811_firmware
cisco ip_phone_8811_firmware
cisco ip_phone_8811_firmware
cisco ip_phone_8811
cisco ip_phone_8832_firmware
cisco ip_phone_8832_firmware
cisco ip_phone_8832_firmware
cisco ip_phone_8832
cisco ip_phone_8841_firmware
cisco ip_phone_8841_firmware
cisco ip_phone_8841_firmware
cisco ip_phone_8841
cisco ip_phone_8845_firmware
cisco ip_phone_8845_firmware
cisco ip_phone_8845_firmware
cisco ip_phone_8845
cisco ip_phone_8851_firmware
cisco ip_phone_8851_firmware
cisco ip_phone_8851_firmware
cisco ip_phone_8851
cisco ip_phone_8861_firmware
cisco ip_phone_8861_firmware
cisco ip_phone_8861_firmware
cisco ip_phone_8861
cisco video_phone_8875_firmware
cisco video_phone_8875_firmware
cisco video_phone_8875_firmware
cisco video_phone_8875_firmware
cisco video_phone_8875
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821_firmware
cisco ip_phone_8821

References

Frequently Asked Questions

What is 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. It has a CVSS v3.1 base score of 7.5 (HIGH).
How severe is CVE-2025-20350? +
CVE-2025-20350 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
What products are affected by CVE-2025-20350? +
CVE-2025-20350 affects products from cisco, specifically: desk_phone_9841, desk_phone_9841_firmware, desk_phone_9851, desk_phone_9851_firmware, desk_phone_9861, desk_phone_9861_firmware, desk_phone_9871, desk_phone_9871_firmware, ip_phone_7811, ip_phone_7811_firmware, ip_phone_7821, ip_phone_7821_firmware, ip_phone_7841, ip_phone_7841_firmware, ip_phone_7861, ip_phone_7861_firmware, ip_phone_8811, ip_phone_8811_firmware, ip_phone_8821, ip_phone_8821_firmware, ip_phone_8832, ip_phone_8832_firmware, ip_phone_8841, ip_phone_8841_firmware, ip_phone_8845, ip_phone_8845_firmware, ip_phone_8851, ip_phone_8851_firmware, ip_phone_8861, ip_phone_8861_firmware, ip_phone_8865, ip_phone_8865_firmware, video_phone_8875, video_phone_8875_firmware. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2025-20350? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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