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

CVE-2020-3161 is rated critical with a CVSS v3.1 base score of 9.8 and affects Cisco Cisco IP Phones, along with 13 other products in NVD’s configuration data. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available. CISA added it to its Known Exploited Vulnerabilities catalog on 2021-11-03, which means exploitation in the wild has been observed.

Vulnerability 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.

Severity breakdown

CVSS v3.1 9.8: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: None. No account or prior access is needed.
  • User interaction: None. No action from any user is needed.
  • Scope: Unchanged. Impact stays within the vulnerable component.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-20: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Affected products

  • Cisco IP Phone 8865 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 8851 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 7841 Firmware: 11.0\(1\)
  • Cisco IP Phone 7821 Firmware: 11.0\(1\)
  • Cisco IP Phone 8811 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 8861 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 8845 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 7861 Firmware: 11.0\(1\)
  • Cisco IP Phone 8841 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 7811 Firmware: 11.0\(1\)
  • Cisco IP Phone 8821 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco IP Phone 8821 Ex Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1
  • Cisco 8831 Firmware: 10.3\(1\)es14; 11.0\(1\); 11.0\(5\)sr1

References