FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, xf_AppUpdateWindowFromSurface reuses a cached XImage whose data pointer references a freed RDPGFX surface buffer, because gdi_DeleteSurface frees surface->data without invalidating the appWindow->image that aliases it. Version 3.23.0 fixes the issue.
Weakness
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Freerdp | Freerdp | * | 3.23.0 (excluding) |
Potential Mitigations
References
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_window.c#L1484-L1492
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_window.c#L1494-L1500
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/client/X11/xf_window.c#L1528
- https://github.com/FreeRDP/FreeRDP/blob/5c7aae27d0417b42b4806c2a5c583ca39dd9ef1e/libfreerdp/gdi/gfx.c#L1224-L1227
- https://github.com/FreeRDP/FreeRDP/commit/169d358734509e82663a0d6a0085ae726d439d8e
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4g54-x8v7-559x
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-4g54-x8v7-559x