Check Point Advisories

Cisco IP Phone Buffer Overflow (CVE-2020-3161)

Vulnerability
Protection

Check Point Reference:	CPAI-2020-0369
Date Published:	21 May 2020
Severity:	Critical
Last Updated:	Wednesday 13 August, 2025
Source:
Industry Reference:	CVE-2020-3161
Protection Provided by:	Security Gateway R81, R80, R77, R75
Who is Vulnerable?	Cisco IP Phone 8865 firmware version 10.3(1)es14 Cisco IP Phone 8865 firmware version 11.0(1) Cisco IP Phone 8865 firmware version 11.0(5)sr1 Cisco IP Phone 8851 firmware version 10.3(1)es14 Cisco IP Phone 8851 firmware version 11.0(1) Cisco IP Phone 8851 firmware version 11.0(5)sr1 Cisco IP Phone 7841 firmware version 11.0(1) Cisco IP Phone 7821 firmware version 11.0(1) Cisco IP Phone 8811 firmware version 10.3(1)es14 Cisco IP Phone 8811 firmware version 11.0(1) Cisco IP Phone 8811 firmware version 11.0(5)sr1 Cisco IP Phone 8861 firmware version 10.3(1)es14 Cisco IP Phone 8861 firmware version 11.0(1) Cisco IP Phone 8861 firmware version 11.0(5)sr1 Cisco IP Phone 8845 firmware version 10.3(1)es14 Cisco IP Phone 8845 firmware version 11.0(1) Cisco IP Phone 8845 firmware version 11.0(5)sr1 Cisco IP Phone 7861 firmware version 11.0(1) Cisco IP Phone 8841 firmware version 10.3(1)es14 Cisco IP Phone 8841 firmware version 11.0(1) Cisco IP Phone 8841 firmware version 11.0(5)sr1 Cisco IP Phone 7811 firmware version 11.0(1) Cisco IP Phone 8821 firmware version 10.3(1)es14 Cisco IP Phone 8821 firmware version 11.0(1) Cisco IP Phone 8821 firmware version 11.0(5)sr1 Cisco IP Phone 8821-EX firmware version 10.3(1)es14 Cisco IP Phone 8821-EX firmware version 11.0(1) Cisco IP Phone 8821-EX firmware version 11.0(5)sr1 Cisco 8831 firmware version 10.3(1)es14 Cisco 8831 firmware version 11.0(1) Cisco 8831 firmware version 11.0(5)sr1
Vulnerability Description	A buffer overflow vulnerability exists in Cisco IP Phone. Successful exploitation of this vulnerability could allow a remote attacker to execute arbitrary code on the affected system or cause application crashes.

Protection Overview

This protection detects attempts to exploit this vulnerability.

In order for the protection to be activated, update your Security Gateway product to the latest IPS update. For information on how to update IPS, go to SBP-2006-05, click on Protection tab and select the version of your choice.

Security Gateway R81 / R80 / R77 / R75

In the IPS tab, click Protections and find the Cisco IP Phone Buffer Overflow (CVE-2020-3161) protection using the Search tool and Edit the protection's settings.
Install policy on all Security Gateways.

This protection's log will contain the following information:

Attack Name: Cisco Protection Violation.
Attack Information: Cisco IP Phone Buffer Overflow (CVE-2020-3161)