CVE-2020-3161: Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability

Vulnerability summary

CVE-2020-3161 is a high (CVSS 10.0) Improper Input Validation vulnerability in Cisco Cisco IP Phones. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 83.86% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities. 2 public exploits are recorded.

Timeline

1. 15-04-2020
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVCisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability
3. 03-05-2022
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

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.

• CWE-20Improper Input ValidationThe product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.