CVE-2023-39351: 
NixOS vulnerability analysis and mitigation

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. CVE-2023-39351 was discovered and disclosed in August 2023, affecting FreeRDP versions up to 2.10.0 and 3.0.0-beta2. The vulnerability affects FreeRDP-based clients only, while the FreeRDP proxy is not affected as image decoding is not done by proxy (GitHub Advisory).

The vulnerability is a Null Pointer Dereference 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 cause a program crash (GitHub Advisory). The vulnerability has been assigned a CVSS v3.1 base score of 7.5 HIGH by NVD and 5.3 MEDIUM by GitHub (NVD).

When exploited, this vulnerability leads to a Denial of Service (DoS) condition through program crash when processing RemoteFX data (GitHub Advisory).

This issue has been addressed in FreeRDP versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade to these or later versions. There are no known workarounds for this vulnerability (GitHub Advisory).