CVE-2021-1568: A vulnerability in Cisco AnyConnect Secure Mobility Client for Windows could allow an authenticated, local attacker to cause a denial of service (DoS)...

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.

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.21%

10.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-789

Affected Software

Vendor	Product	Versions
Cisco	Anyconnect Secure Mobility Client	< 4.10.01075

References

Timeline

Published: Jun 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-1568?

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.

How severe is CVE-2021-1568?

CVE-2021-1568 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.21% probability of exploitation in the next 30 days.

How do I fix CVE-2021-1568?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.