Cisco disclosed a high-severity vulnerability, tracked as CVE-2022-20968, impacting its IP Phone 7800 and 8800 Series. A vulnerability in the Cisco Discovery Protocol processing feature of Cisco IP Phone 7800 and 8800 Series firmware could allow an unauthenticated, adjacent attacker to cause a stack overflow on an affected device. 

This vulnerability is due to insufficient input validation of received Cisco Discovery Protocol packets. An attacker could exploit this vulnerability by sending crafted Cisco Discovery Protocol traffic to an affected device. 

A successful exploit could allow the attacker to cause a stack overflow, resulting in possible remote code execution or a denial of service (DoS) condition on an affected device. Cisco Product Security Incident Response Team (PSIRT) is aware of the availability of a proof-of-concept exploit code for this vulnerability.