CVE-2021-41159: FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. All FreeRDP clients prior to version 2.4.1 u...

Description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. All FreeRDP clients prior to version 2.4.1 using gateway connections (`/gt:rpc`) fail to validate input data. A malicious gateway might allow client memory to be written out of bounds. This issue has been resolved in version 2.4.1. If you are unable to update then use `/gt:http` rather than /gt:rdp connections if possible or use a direct connection without a gateway.

Metrics

CVSS 3.1

8.8/10

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

EPSS Probability

1.35%

67.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Freerdp	Freerdp	< 2.4.1
Fedoraproject	Fedora	35

References

Timeline

Published: Oct 21, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-41159?

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. All FreeRDP clients prior to version 2.4.1 using gateway connections (`/gt:rpc`) fail to validate input data. A malicious gateway might allow client memory to be written out of bounds. This issue has been resolved in version 2.4.1. If you are unable to update then use `/gt:http` rather than /gt:rdp connections if possible or use a direct connection without a gateway.

How severe is CVE-2021-41159?

CVE-2021-41159 has a CVSS score of 8.8/10 (HIGH severity). The EPSS model estimates a 1.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-41159?

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.