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

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2021-11-03
• EPSS: 84% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official 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.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 3 May 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• packetstormsecurity.com/files/157265/Cisco-IP-Phone-11.7-Denial-Of-Service.htmlExploitThird Party AdvisoryVDB Entry
• tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-voip-phones-rce-…Vendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource