// For flags

CVE-2021-41160

Improper region checks in FreeRDP allow out of bound write to memory

Severity Score

8.8
*CVSS v3.1

Exploit Likelihood

< 1%
*EPSS

Affected Versions

4
*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

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.

FreeRDP es una implementación libre del Protocolo de Escritorio Remoto (RDP), publicada bajo la licencia Apache. En las versiones afectadas, un servidor malicioso podría desencadenar escrituras fuera de límites en un cliente conectado. Las conexiones que usan GDI o SurfaceCommands para enviar actualizaciones de gráficos al cliente podrían enviar rectángulos de anchura/altura "0" o fuera de límites para desencadenar escrituras fuera de límites. Con una anchura o altura de "0" la asignación de memoria será "0" pero las comprobaciones de límites faltantes permiten escribir en el puntero en esta región (no asignada). Este problema ha sido parcheado en FreeRDP versión 2.4.1

A flaw was found in the FreeRDP client where it fails to validate input data when using connections with GDI or SurfaceCommands. This flaw could allow a malicious server sending graphics updates to a client to cause an out of bounds write in client memory using a specially crafted input. The highest threat from this flaw is that it could allow arbitrary code to be executed on the target system.

It was discovered that FreeRDP incorrectly handled certain inputs. An attacker could possibly use this issue to execute arbitrary code or cause a crash. It was discovered that FreeRDP incorrectly handled certain connections. An attacker could possibly use this issue to execute arbitrary code or cause a crash.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
High
Availability
None
Attack Vector
Network
Attack Complexity
Medium
Authentication
None
Confidentiality
Partial
Integrity
Partial
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-09-15 CVE Reserved
  • 2021-10-21 CVE Published
  • 2022-12-27 First Exploit
  • 2024-08-04 CVE Updated
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-787: Out-of-bounds Write
CAPEC
Affected Vendors, Products, and Versions (4)