CVE-2020-3161
Cisco IP Phones Web Server Remote Code Execution and Denial-of-Service Vulnerability
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
- Public exploits
- 1 in Exploit-DB · first 17 April 2020
- 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
EPSS 83.9% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
CISA notes
Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2020-3161
Public exploits (1)
Entries in Exploit-DB that cite this CVE. Links go to the Exploit-DB page and to the file in the public repository; nothing is hosted here. A verified tick means the Exploit-DB team confirmed the exploit works against the stated version.
References
- http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXsVendor Advisory
- http://packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.htmlExploit, Third Party Advisory, VDB Entry
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-dos-rB6EeRXsVendor Advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3161US Government Resource
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.