CVE-2020-3111 (AKA: CDPwn)

A vulnerability in the Cisco Discovery Protocol implementation for the Cisco IP Phone could allow an unauthenticated, adjacent attacker to remotely execute code with root privileges or cause a reload of an affected IP phone. The vulnerability is due to missing checks when processing Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a crafted Cisco Discovery Protocol packet to the targeted IP phone. 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 denial of service (DoS) condition. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

Recent assessments:

zeroSteiner at February 06, 2020 7:45pm UTC reported:

This vulnerability can reportedly only be used to trigger a denial of service condition on VoIP phones, potentially in a wide spread fashion. This would likely disrupt business but would not grant the attacker access to any sensitive information. Business in which affected VoIP phones are used to generate revenue such as commercial and support call centers.

An attacker would need to be on the local area network, directly attached to the vulnerable switch running IOS-XR. This is due to CDP traffic not being forwarded across network boundaries. An attacker leveraging this vulnerability would likely either be physically in the building or have compromised a host which is physically in the building. Successful exploitation would create a denial of service condition…

Assessed Attacker Value: 2
Assessed Attacker Value: 2Assessed Attacker Value: 4