Arch Linux Security Advisory ASA-202110-11
=========================================
Severity: Medium
Date    : 2021-10-29
CVE-ID  : CVE-2021-41159 CVE-2021-41160
Package : freerdp
Type    : arbitrary code execution
Remote  : Yes
Link    : https://security.archlinux.org/AVG-2488

Summary
======
The package freerdp before version 2:2.4.1-1 is vulnerable to arbitrary
code execution.

Resolution
=========
Upgrade to 2:2.4.1-1.

# pacman -Syu "freerdp>=2:2.4.1-1"

The problems have been fixed upstream in version 2.4.1.

Workaround
=========
CVE-2021-41159 can be mitigated by using a /gt:http connection or a
direct connection without gateway. No known mitigation exists for
CVE-2021-41160.

Description
==========
- CVE-2021-41159 (arbitrary code execution)

A security issue has been found in FreeRDP before version 2.4.1.
Improper client input validation for gateway connections (/gt:rpc)
allows a malicious gateway to overwrite client memory.

- CVE-2021-41160 (arbitrary code execution)

A security issue has been found in FreeRDP before version 2.4.1. 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.

Impact
=====
A malicious RDP server or gateway could cause remote code execution on
a connected client.

References
=========
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-vh34-m9h7-95xq
https://github.com/FreeRDP/FreeRDP/commit/07b789c88010766c230c8f10ac748523b86e9305
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-7c9r-6r2q-93qg
https://github.com/FreeRDP/FreeRDP/commit/217e0caa181fc1690cf84dd6a3ba1a4f90c02692
https://security.archlinux.org/CVE-2021-41159
https://security.archlinux.org/CVE-2021-41160