CVE-2021-1568: Cisco AnyConnect Secure Mobility Client for Windows Denial of Service Vulnerability

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-06-16 · updated 2026-06-17
Weakness: CWE-789

Description

A vulnerability in Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system. This vulnerability is due to uncontrolled memory allocation. An attacker could exploit this vulnerability by copying a crafted file to a specific folder on the system. A successful exploit could allow the attacker to crash the VPN Agent service when the affected application is launched, causing it to be unavailable to all users of the system. To exploit this vulnerability, the attacker must have valid credentials on a multiuser Windows system.

Affected products

Cisco AnyConnect Secure Mobility Client: before 4.10.01075 — fixed in 4.10.01075

How to fix

Upgrade to a fixed version: Cisco AnyConnect Secure Mobility Client 4.10.01075. Check the vendor advisory for mitigations.

References

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