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

CISA Known Exploited Vulnerabilities

Name

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

Vendor

Cisco

Product

Cisco IP Phones

Added to the catalog

2021-11-03

Due date for US federal agencies

2022-05-03

Weaknesses

CWE-20

Catalog version

2026.10.30

Cisco IP Phones contain an improper input validation vulnerability for HTTP requests. Exploitation could allow an attacker to execute code remotely with root privileges or cause a denial-of-service (DoS) condition.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://nvd.nist.gov/vuln/detail/CVE-2020-3161

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2020-04-15T20:15:15.097

Last modified

2026-06-17T03:17:31.293

Weaknesses

CWE-20

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.

References

• http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html (Exploit, Third Party Advisory, VDB Entry)
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXs (Vendor Advisory)
• http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html (Exploit, Third Party Advisory, VDB Entry)
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXs (Vendor Advisory)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3161 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:43.468Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2020-3161

CVE record

Title (CNA)

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

Assigner

cisco

State

PUBLISHED

Published

2020-04-15T20:10:11.570Z

Updated

2025-10-21T23:35:45.888Z

Problem types

CWE-20

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.

References

• 20200415 Cisco IP Phones Web Server Remote Code Execution and Denial of Service Vulnerability
• http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.html

Read on 2026-11-03T01:04:24.683Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2020/3xxx/CVE-2020-3161.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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