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

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 inp

01What is this vulnerability?

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…

02Affected products

Vendor	Product	Versions
Cisco	Cisco IP phone	n/a

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2021-11-03. Ransomware use: Unknown.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-04-15T20:10:11.570Z
• Last modified: 2025-10-21T23:35:45.888Z
• Added to CISA KEV: 2021-11-03
• BOD 22-01 due: 2022-05-03

09References

• tools.cisco.com — https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-v…
• packetstormsecurity.com — http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Servic…