FreeRDP before 3.31.0 contains a heap out-of-bounds read vulnerability in the general_ChromaV1ToYUV444 function during AVC444 chroma plane reconstruction. A malicious RDP server can craft a RFX_AVC444_BITMAP_STREAM with specific frame geometry to trigger an out-of-bounds memory read past the allocated luma plane.

FreeRDP versions 3.0.0 through 3.30.0 (before 3.31.0) transmit uninitialized heap memory in Save Session Info PDU reserved padding fields. Three PDU writers in libfreerdp/core/info.c (rdp_write_logon_info_v2, rdp_write_logon_info_plain, and rdp_write_logon_info_ex) use Stream_Seek instead of Stream_Zero for reserved pad bytes (up to 576 bytes), leaving previously freed heap contents in the outgoing PDU. Because the send buffer is allocated with malloc (not zeroed), stale heap data — which may include cleartext credentials from prior sessions — can be sent to the receiving peer. FreeRDP-based servers using rdpUpdate::SaveSessionInfo and freerdp-proxy (which forwards these PDUs) are affected, allowing disclosure of server/proxy process memory to a downstream client.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP H.264 decoder backends can return YUV planes sized from the bitstream without comparing the decoded width and height to the RDPGFX surface dimensions used to validate region rectangles. A malicious RDP server can provide an AVC420 or AVC444 bitstream whose decoded frame is smaller than the negotiated surface, causing yuv420_context_decode and the YUV-to-RGB conversion paths to read beyond the decoder-owned planes in libfreerdp/codec/h264.c and the selected H.264 backend. This can disclose client memory or crash the client. This issue is fixed in version 3.27.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, the glyph_cache_get function in libfreerdp/cache/glyph.c checks whether index is greater than cache->number instead of greater than or equal to it. A malicious RDP server can use GLYPH_FRAGMENT_USE replay in update_process_glyph_fragments to make the default cache receive index 254 when cache->number is 254, reading one pointer beyond the entries array and dereferencing it as a glyph. This can crash the client and may disclose adjacent heap data. This issue is fixed in version 3.27.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdp_dsp_decode_opus in libfreerdp/codec/dsp.c calls Stream_EnsureRemainingCapacity on context->common.buffer even though opus_decode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVE_FORMAT_OPUS with a client built with WITH_OPUS enabled and WITH_DSP_FFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPool_Take destination used by channels/rdpsnd/client/rdpsnd_main.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, FreeRDP clients using TS Gateway accept a server-controlled max_xmit_frag value in libfreerdp/core/gateway/rpc_bind.c without bounding it to the 4088-byte ReceiveFragment allocation. A malicious gateway can advertise 65535 and then send a response fragment of the same length, causing rpc_channel_read in libfreerdp/core/gateway/rpc.c to write up to 65535 bytes into the smaller ReceiveFragment buffer. This can crash the client and may permit code execution through attacker-controlled heap corruption. This issue is fixed in version 3.27.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.29.0, planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c verify that a control byte exists but do not verify that the source buffer contains the zero to fifteen raw bytes declared by that control byte. A malicious RDP server can send a truncated planar bitmap or surface update whose final control byte claims additional raw bytes, causing the decoder to read beyond pSrcData while processing a color plane. This can crash the client and may disclose adjacent memory. This issue is fixed in version 3.29.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, rdpsnd_server_recv_formats in channels/rdpsnd/server/rdpsnd_main.c frees context->client_formats on a malformed Client Audio Formats PDU without clearing the owning pointer or num_client_formats. An authenticated RDP client can trigger an error such as a cbSize larger than the remaining record, leave the dangling pointer in the server context, and cause rdpsnd_server_context_free to free the same allocation again at session teardown. This reliably terminates the server and can create allocator-dependent heap corruption. This issue is fixed in version 3.28.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, an authenticated RDP client can advertise DVI ADPCM with nBlockAlign equal to 8 and nChannels equal to 2 to make the `bs` calculation in rdpsnd_server_select_format in channels/rdpsnd/server/rdpsnd_main.c equal zero. The subsequent out_frames modulo `bs` operation raises SIGFPE and terminates the server-side rdpsnd channel process. This vulnerability fixed in 3.28.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.0, rpc_client_recv_fragment in libfreerdp/core/gateway/rpc_client.c ensures the response reassembly stream capacity using only the server-declared alloc_hint rather than the actual StubLength about to be written. A malicious TS Gateway can send a PTYPE_RESPONSE with a small alloc_hint and a much larger frag_length, causing Stream_Write to copy attacker-controlled stub data beyond the 4096-byte pdu->s buffer. This can crash the client and may permit code execution through heap corruption. This issue is fixed in version 3.27.0.