CVE-2021-41160 Improper region checks in FreeRDP allow out of bound write to memory

Medium 5.3 Published 21 Oct 2021 Updated 3 Nov 2025

A malicious RDP server can trigger out-of-bounds writes in FreeRDP clients via malformed graphics updates, potentially allowing remote code execution.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Local or same network only
Victim action needed: Not needed
Fix: Available

What is CVE-2021-41160?

CVE-2021-41160 is a medium-severity memory corruption vulnerability in Fedoraproject Fedora, published on 21 Oct 2021. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions a malicious server might trigger out of bound writes in a connected client. Connections using GDI or SurfaceCommands to send graphics updates to the client might send `0` width/height or out of bound rectangles to trigger out of bound writes. With `0` width or heigth the memory allocation will be `0` but the missing bounds checks allow writing to the pointer at this (not allocated) region. This issue has been patched in FreeRDP 2.4.1.

Weakness: CWE-787

Which versions are affected by CVE-2021-41160?

It affects 2 products.

Products include Fedoraproject Fedora, Freerdp Freerdp.

How do I fix CVE-2021-41160?

Upgrade to a fixed version.

Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.

Is CVE-2021-41160 being exploited?

There is no known exploitation of CVE-2021-41160 in the wild and no public exploit code.

Public exploit code: 1 proofs of concept on GitHub.

All Fedoraproject Fedora vulnerabilities

Sources

Also known as CLEANSTART-2024-OE64928, DEBIAN-CVE-2021-41160, GHSA-7c9r-6r2q-93qg, OESA-2021-1424, UBUNTU-CVE-2021-41160.