CVE-2023-39351: FreeRDP Null Pointer Dereference leading denial of service

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2023-08-31 · updated 2026-06-17
Weakness: CWE-476

Description

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions of FreeRDP are subject to a Null Pointer Dereference leading a crash in the RemoteFX (rfx) handling. Inside the `rfx_process_message_tileset` function, the program allocates tiles using `rfx_allocate_tiles` for the number of numTiles. If the initialization process of tiles is not completed for various reasons, tiles will have a NULL pointer. Which may be accessed in further processing and would cause a program crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Affected products

Debian Linux: 10.0
Fedoraproject Fedora: 37, 38, 39
FreeRDP: before 2.11.0; 3.0.0-beta1, 3.0.0-beta2 — fixed in 2.11.0

How to fix

Upgrade to a fixed version: FreeRDP 2.11.0. Check the vendor advisory for mitigations.

References

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