Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability (CVE-2020-3161) | HOL Guard CVE

High severityKnown ExploitedCVE-2020-3161

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

Answer in brief

CVE-2020-3161 records a High severity vulnerability in Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability. The current sources mark it as known exploited. The current feed maps Cisco/Cisco IP phone (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Apr 15, 2020Updated Oct 21, 2025Source checked Sep 17, 2026First seen by HOL May 24, 2026Material review Oct 21, 2025

Upstream Advisory

Key facts

Risk: High
Exploitation: Known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. Known-exploitation status makes exposure review time-sensitive. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Cisco/Cisco IP phone (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Cisco/Cisco IP phonegeneric	n/a	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Cisco/Cisco IP phone.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Apr 15, 2020
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 21, 2025
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
May 24, 2026
Added to CISA KEV
Nov 3, 2021
Evidence: source:kev:kev:kev:record

Sources and claim methodology

Upstream source 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.

Quoted source text, attributed separately from HOL analysis.