A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.
Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ssl-dos-kxG8mpUA
This advisory is part of the November 2023 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. For a complete list of the advisories and links to them, see Cisco Event Response: November 2023 Semiannual Cisco ASA, FMC, and FTD Software Security Advisory Bundled Publication.
Security Impact Rating: Medium
CVE: CVE-2023-20042
Source:: Cisco Security Advisories