CVE-2022-20968: Cisco IP Phone 7800 and 8800 Series Stack Overflow Vulnerability

Cisco on Thursday released a patch to contain a high-risk security vulnerability in its Cisco IP Phone 7800 and 8800 Series products that could be abused to execute arbitrary code or cause a denial of service condition on the system.

The bug, assigned the identifier CVE-2022-20968 (CVSS score: 8.1), has been described as a stack-based buffer overflow, caused by improper bounds checking. By sending specially crafted Cisco Discovery Protocol packets, a remote attacker could overflow a buffer and execute arbitrary code or cause a denial of service condition on the system.

Image: Cisco

“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 warned in an advisory.

CVE-2022-20968 impacts the Cisco Discovery Protocol processing feature of Cisco IP Phone 7800 and 8800 Series (except Cisco Wireless IP Phone 8821) firmware.

Cisco credited Qian Chen of the Codesafe Team of Legendsec at QI-ANXIN Group for reporting the bug.

The Cisco PSIRT is aware that proof-of-concept exploits code is available for this vulnerability but has not found any malicious use of the vulnerability.