CVE-2023-20240: Cisco AnyConnect Secure Mobility Client

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

Multiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system. These vulnerabilities are due to an out-of-bounds memory read from Cisco Secure Client Software. An attacker could exploit these vulnerabilities by logging in to an affected device at the same time that another user is accessing Cisco Secure Client on the same system, and then sending crafted packets to a port on that local host. A successful exploit could allow the attacker to crash the VPN Agent service, causing it to be unavailable to all users of the system. To exploit these vulnerabilities, the attacker must have valid credentials on a multi-user system.

Affected products

• Cisco AnyConnect Secure Mobility Client: version 4.9.00086 only; version 4.9.01095 only; version 4.9.02028 only; version 4.9.03047 only; version 4.9.03049 only; version 4.9.04043 only; …
• Cisco Secure Client: version 4.10.00093 only; version 4.10.01075 only; version 4.10.02086 only; version 4.10.03104 only; version 4.10.04065 only; version 4.10.04071 only; …

Published 2023-11-22. Last modified 2026-06-17.