Is CVE-2023-20042 actively exploited?

No active exploitation of CVE-2023-20042 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2023-20042 be exploited remotely?

Yes. CVE-2023-20042 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2023-20042?

CVE-2023-20042 has a CVSS score of 8.6 (HIGH).

HOME VULNERABILITIESCVE-2023-20042

HIGH

CVE-2023-20042

CWE-404Published: November 1, 2023· Updated: Jun 17, 2026

8.6

CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2023-20042 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.6.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.