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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2020-3161

Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability

KEVCRITICAL 9.8EPSS 83.9%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 3 May 2022). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

A vulnerability in the web server for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web server of a targeted device. A successful exploit could allow the attacker to remotely execute code with root privileges or cause a reload of an affected IP phone, resulting in a DoS condition.

CVSS 3.1
9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS
83.86% probability · 100th percentile
CISA KEV
Listed 3 November 2021 · due 3 May 2022
Weakness
CWE-20
Affected
cisco/ip phone 8865 firmware · cisco/ip phone 8851 firmware · cisco/ip phone 7841 firmware · cisco/ip phone 7821 firmware · cisco/ip phone 8811 firmware · cisco/ip phone 8861 firmware · cisco/ip phone 8845 firmware · cisco/ip phone 7861 firmware · cisco/ip phone 8841 firmware · cisco/ip phone 7811 firmware · cisco/ip phone 8821 firmware · cisco/ip phone 8821-ex firmware · cisco/8831 firmware
Source
psirt@cisco.com

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2020-3161

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.