CVE-2021-34781 – Cisco Firepower Threat Defense Software SSH Connections Denial of Service Vulnerability

https://notcve.org/view.php?id=CVE-2021-34781

A vulnerability in the processing of SSH connections for multi-instance deployments of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. This vulnerability is due to a lack of proper error handling when an SSH session fails to be established. An attacker could exploit this vulnerability by sending a high rate of crafted SSH connections to the instance. A successful exploit could allow the attacker to cause resource exhaustion, which causes a DoS condition on the affected device. The device must be manually reloaded to recover. • https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-rUDseW3r • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer CWE-755: Improper Handling of Exceptional Conditions •