Freerdp vulnerabilities

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the fix for the heap-use-after-free described in CVE-2026-24680 is incomplete. While the vulnerable execution flow referenced in the advisory exists in the SDL2 implementation, the fix appears to have been applied only to the SDL3 code path. In the SDL2 implementation, the pointer is not nulled after free. This creates a situation where the advisory suggests the vulnerability is fully resolved, while builds or environments still using SDL2 may retain the vulnerable logic. A complete fix is available in version 3.23.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `rail_window_free` dereferences a freed `xfAppWindow` pointer during `HashTable_Free` cleanup because `xf_rail_window_common` calls `free(appWindow)` on title allocation failure without first removing the entry from the `railWindows` hash table, leaving a dangling pointer that is freed again on disconnect. Version 3.23.0 fixes the vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, in the RLE planar decode path, `planar_decompress_plane_rle()` writes into `pDstData` at `((nYDst+y) * nDstStep) + (4*nXDst) + nChannel` without verifying that `(nYDst+nSrcHeight)` fits in the destination height or that `(nXDst+nSrcWidth)` fits in the destination stride. When `TempFormat != DstFormat`, `pDstData` becomes `planar->pTempData` (sized for the desktop), while `nYDst` is only validated against the **surface** by `is_within_surface()`. A malicious RDP server can exploit this to perform a heap out-of-bounds write with attacker-controlled offset and pixel data on any connecting FreeRDP client. The OOB write reaches up to 132,096 bytes past the temp buffer end, and on the brk heap (desktop ≤ 128×128), an adjacent `NSC_CONTEXT` struct's `decode` function pointer is overwritten with attacker-controlled pixel data — control-flow–relevant corruption (function pointer overwritten) demonstrated under deterministic heap layout (`nsc->decode = 0xFF414141FF414141`). Version 3.23.0 fixes the vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a malicious RDP server can trigger a heap buffer overflow in FreeRDP clients using the GDI surface pipeline (e.g., `xfreerdp`) by sending an RDPGFX ClearCodec surface command with an out-of-bounds destination rectangle. The `gdi_SurfaceCommand_ClearCodec()` handler does not call `is_within_surface()` to validate the command rectangle against the destination surface dimensions, allowing attacker-controlled `cmd->left`/`cmd->top` (and subcodec rectangle offsets) to reach image copy routines that write into `surface->data` without bounds enforcement. The OOB write corrupts an adjacent `gdiGfxSurface` struct's `codecs*` pointer with attacker-controlled pixel data, and corruption of `codecs*` is sufficient to reach an indirect function pointer call (`NSC_CONTEXT.decode` at `nsc.c:500`) on a subsequent codec command — full instruction pointer (RIP) control demonstrated in exploitability harness. Users should upgrade to version 3.23.0 to receive a patch.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_rail_server_local_move_size` dereferences a freed `xfAppWindow` pointer because `xf_rail_get_window` returns an unprotected pointer from the `railWindows` hash table, and the main thread can concurrently delete the window (via a window delete order) while the RAIL channel thread is still using the pointer. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_rail_server_execute_result` indexes the global `error_code_names[]` array (7 elements, indices 0–6) with an unchecked `execResult->execResult` value received from the server, allowing an out-of-bounds read when the server sends an `execResult` value of 7 or greater. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Versions on the 2.x branch prior to to 2.11.8 and on the 3.x branch prior to 3.23.0 have an out-of-bounds read vulnerability in the FreeRDP client's RDPGFX channel that allows a malicious RDP server to read uninitialized heap memory by sending a crafted WIRE_TO_SURFACE_2 PDU with a `bitmapDataLength` value larger than the actual data in the packet. This can lead to information disclosure or client crashes when a user connects to a malicious server. Versions 2.11.8 and 3.23.0 fix the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, the RDPSND async playback thread can process queued PDUs after the channel is closed and internal state is freed, leading to a use after free in rdpsnd_treat_wave. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. ainput_send_input_event caches channel_callback in a local variable and later uses it without synchronization; a concurrent channel close can free or reinitialize the callback, leading to a use after free. Prior to 3.22.0, This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, audin_server_recv_formats frees an incorrect number of audio formats on parse failure (i + i), leading to out-of-bounds access in audio_formats_free. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, aAsynchronous bulk transfer completions can use a freed channel callback after URBDRC channel close, leading to a use after free in urb_write_completion. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, sdl_Pointer_New frees data on failure, then pointer_free calls sdl_Pointer_Free and frees it again, triggering ASan UAF. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, A capture thread sends sample responses using a freed channel callback after a device channel close, leading to a use after free in ecam_channel_write. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, AUDIN format renegotiation frees the active format list while the capture thread continues using audin->format, leading to a use after free in audio_format_compatible. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, urb_select_interface can free the device's MS config on error but later code still dereferences it, leading to a use after free in libusb_udev_select_interface. This vulnerability is fixed in 3.22.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.22.0, video_timer can send client notifications after the control channel is closed, dereferencing a freed callback and triggering a use after free. This vulnerability is fixed in 3.22.0.