FreeRDP vulnerabilities

FreeRDP before 3.32.0 contains a NULL pointer dereference vulnerability in the client video redirection channel. A malicious server can send a Geometry CLEAR message that nulls presentation->geometry, then send VideoData that dereferences it, crashing the client.

FreeRDP 3.11.0 before 3.32.1 contains a reachable assertion vulnerability in urb_isoch_transfer. A malicious RDP server can send unvalidated OutputBufferSize values, triggering an assertion in libusb_udev_isoch_transfer and terminating the client.

FreeRDP versions before 3.31.0 contain a heap-based buffer overflow in nego_send_negotiation_request when processing Server Redirection PDU messages with attacker-controlled LoadBalanceInfo fields. A malicious RDP server can trigger the overflow by sending an arbitrary-length field that gets written to a fixed 512-byte buffer without validation, causing client crashes or potential code execution when chained with memory disclosure.

FreeRDP versions before 3.31.0 contain an uninitialized heap memory disclosure vulnerability in the urbdrc USB redirection channel. A malicious RDP server can induce failing USB transfers to read uninitialized heap memory from the client, defeating ASLR and enabling remote code execution when chained with memory corruption vulnerabilities.

FreeRDP before 3.31.0 contains an integer overflow in the audin Apple backends when processing FramesPerPacket values from MSG_SNDIN_OPEN messages. Attackers can supply crafted FramesPerPacket values that cause AudioQueueAllocateBuffer size computation to wrap, resulting in undersized buffer allocation and potential out-of-bounds access.

FreeRDP before 3.31.0 contains a denial-of-service vulnerability in the URBDRC control-transfer request path that fails to validate OutputBufferSize before forwarding to the libusb backend. A malicious RDP server can send a control-transfer request with OutputBufferSize set to 65536, triggering a reachable assertion that terminates the client process.

FreeRDP versions before 3.31.0 contain an integer overflow in WinPR's Stream_EnsureRemainingCapacity function that allows remote attackers to cause denial of service. A malicious RD Gateway peer can send a WebSocket Ping frame with a crafted 64-bit extended payload length to trigger integer wraparound, resulting in a double free that crashes the FreeRDP client during connection.

FreeRDP before 3.31.0 contains a buffer over-read vulnerability in the rts_read_result function within the RPC gateway transport parser. Attackers can send a malicious BIND_ACK PDU with a truncated result entry to trigger an out-of-bounds read causing process abort.

FreeRDP versions before 3.31.0 fail to validate MonitorIds array values when parsing RDP connection files, allowing unbounded array indexing in xf_detect_monitors. Attackers can craft a malicious RDP file with an out-of-range selectedmonitors value to trigger out-of-bounds heap read and write operations when opened in xfreerdp.

FreeRDP before 3.31.0 contains a use-after-free vulnerability in the smartcard RDPDR device handler when worker thread creation fails after device registration. An attacker can trigger thread creation failure during channel setup, causing device pointer deallocation while devman retains a reference, leading to crash or code execution.

FreeRDP before 3.31.0 contains an out-of-bounds read vulnerability in the URBDRC channel's func_get_ep_desc function that indexes interface arrays by position instead of protocol field InterfaceNumber. A malicious RDP server can send a crafted SELECT_CONFIGURATION message with permuted InterfaceNumber values to read past allocated heap memory and crash the client.

FreeRDP before 3.31.0 fails to validate client-supplied DesktopWidth and DesktopHeight values during GCC negotiation, allowing remote attackers to crash the server. Attackers can send crafted RDP packets with zero or oversized dimensions to trigger division-by-zero or assertion failures in multifragment update capability calculations, terminating the server process.

FreeRDP before 3.31.0 contains a null pointer dereference vulnerability in gdi_surface_bits when processing Surface Bits commands with NSCodec codec ID. A malicious RDP server can crash a FreeRDP client by sending a crafted Surface Bits command claiming to use NSCodec, even when the codec is disabled.

FreeRDP versions before 3.31.0 contain a heap buffer overflow vulnerability in nego_send_negotiation_request() that fails to validate the LB_LOAD_BALANCE_INFO field length before writing to a fixed 512-byte buffer. A malicious RDP server or man-in-the-middle can send a Server Redirection PDU with an oversized LB_LOAD_BALANCE_INFO value to overflow the buffer with attacker-controlled content.

FreeRDP versions before 3.31.0 contain an infinite-loop denial of service in the pool_decode_rect function when decoding AVC444 metablocks with more region rectangles than preallocated worker array size. A malicious RDP server can send crafted AVC444 graphics updates causing the threaded decode path to loop indefinitely.

FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in the urbdrc client channel's urb_send_current_frame_number_result() function. A malicious RDP server can send a crafted 28-byte USB redirection message to trigger a 4-byte write past the allocated 16-byte buffer.

FreeRDP before 3.31.0 contains an out-of-bounds read vulnerability in the rdpdr_dump_packet function due to 32-bit unsigned integer wraparound in buffer bounds validation. A malicious RDP server can send a crafted RDPDR packet with computerNameLen set to 0xFFFFFFF0 to bypass bounds checks and trigger memory reads past the packet buffer.

FreeRDP versions before 3.31.0 contain an out-of-bounds write vulnerability in server-side static virtual channel handling when CHANNEL_OPTION_SHOW_PROTOCOL is enabled. Authenticated clients can queue oversized channel messages that cause buffer underflow and corrupt heap memory including live pointers, potentially enabling code execution.

FreeRDP server versions before 3.31.0 contain a use-after-free vulnerability in the DRDYNVC parser that dereferences a channel pointer after releasing the synchronization lock. Authenticated clients can race AUDIN channel closure messages against DRDYNVC data parsing to trigger heap-use-after-free when accessing freed channel objects.

FreeRDP versions before 3.31.0 contain an information disclosure vulnerability in the RDPGFX server's ResetGraphics PDU serializer that fails to initialize padding bytes in the fixed 340-byte wire format. Attackers can receive uninitialized heap memory including live pointers and GLib function addresses transmitted in the PDU.

FreeRDP versions before 3.31.0 contain an out-of-bounds read vulnerability in smartcard response decoders that fail to validate ATR length fields against fixed inline arrays. Authenticated RDP clients can send oversized ATR lengths in PAKID_CORE_DEVICE_IOCOMPLETION responses to trigger reads past stack or heap objects.

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 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.

In FreeRDP before 3.28.0, rdpsnd_server_recv_formats frees context->client_formats on a malformed Client Audio Formats PDU without clearing the pointer or count. An authenticated RDP client can trigger an error, leaving a dangling pointer, leading to a double-free at session teardown. This can crash the server and cause heap corruption.

FreeRDP prior to 3.28.0 has a vulnerability where 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 prior to 3.27.0 has a vulnerability in freerdp_image_copy_from_icon_data in libfreerdp/codec/color.c where nWidth multiplied by nHeight multiplied by FreeRDPGetBytesPerPixel(format) is calculated in 32-bit arithmetic. A malicious RDP server can send a RAIL TS_ICON_INFO update with dimensions such as 32768 by 32768 and 32 bits per pixel so the required-size calculation wraps, bypassing the cbBitsColor source bounds check before freerdp_image_copy_no_overlap reads attacker-controlled icon data. This affects RemoteApp clients using the vulnerable library path, while xfreerdp has a caller-side mitigation. This issue is fixed in version 3.27.0.

FreeRDP prior to 3.27.0 has a vulnerability in the glyph_cache_get function in libfreerdp/cache/glyph.c which 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.

In FreeRDP before 3.27.0, clients using TS Gateway accept a server-controlled max_xmit_frag value without bounding it to the ReceiveFragment allocation. A malicious gateway can advertise 65535 and send a response fragment of that length, causing a buffer overflow in the ReceiveFragment buffer. This can crash the client and may permit code execution.

In FreeRDP before 3.27.0, H.264 decoder backends can return YUV planes sized from the bitstream without comparing to the RDPGFX surface dimensions. A malicious RDP server can provide an AVC420 or AVC444 bitstream with a smaller decoded frame, causing out-of-bounds reads in the decoder. This can disclose client memory or crash the client.

FreeRDP prior to version 3.30.0 has a vulnerability in server-side RDSTLS that accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ. This allows a remote unauthenticated client to bypass RedirectionGuid, username, domain, or password checks.

FreeRDP before 3.29.0 has integer overflows in the audin channel across ALSA, sndio, WinMM, and OpenSL ES backends. A malicious server can supply a FramesPerPacket value causing allocation size wraparound.

FreeRDP versions up to 3.28.0 contain an out-of-bounds read vulnerability in the RDP6 planar RLE bitmap decoder functions planar_decompress_plane_rle and planar_decompress_plane_rle_only in libfreerdp/codec/planar.c. Only the 1-byte control byte is bounds-checked; the subsequent 0–15 attacker-declared raw bytes are read without validating that the source buffer contains them. A malicious or compromised RDP server can send a truncated planar-encoded bitmap or surface update, causing the client to read past the end of the source buffer.

FreeRDP Windows client before version 3.29.0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code execution when a user performs a paste operation.

FreeRDP before 3.29.0 contains a null pointer dereference vulnerability in smartcard device control request cleanup when reader-state decoding fails. Attackers can send malformed smartcard IRP requests with non-zero cReaders and truncated reader-state data to crash the process via null pointer access in free_reader_states functions.

FreeRDP before version 3.29.0 contains a reachable assertion (WINPR_ASSERT(OutputBufferLength == BytesReturned)) in serial_process_irp_device_control() in channels/serial/client/serial_main.c. When serial device redirection is enabled and a server-controlled IRP_MJ_DEVICE_CONTROL request specifies an unsupported IOCTL with a non-zero OutputBufferLength, CommDeviceIoControl() can fail with BytesReturned = 0, causing the mismatch to trigger the assertion and abort the client process (denial of service).

FreeRDP before version 3.29.0 (affected versions <= 3.28.0) contains a divide-by-zero vulnerability in the rdpecam camera redirection client. ecam_dev_process_start_streams_request() parses a server-controlled CAM_MEDIA_TYPE_DESCRIPTION from a StartStreamsRequest PDU but validates only Format and Flags, not FrameRateDenominator. When a malicious or compromised RDP server sends a StartStreamsRequest with FrameRateDenominator set to zero, ecam_encoder_context_init() computes FrameRateNumerator / FrameRateDenominator, causing an integer division by zero (SIGFPE) and termination of the FreeRDP client process.

FreeRDP before 3.29.0 contains out-of-bounds read vulnerabilities in the async update message proxy for the PolygonSC and PolygonCB primary drawing orders. When AsyncUpdate is enabled (e.g., xfreerdp /async-update), update_message_PolygonSC() and update_message_PolygonCB() allocate a fresh points array but copy point data from the address of the order structure instead of from polygonSC->points / polygonCB->points, resulting in a client-side out-of-bounds read. A malicious or compromised RDP server sending crafted PolygonSC/PolygonCB update orders can trigger memory disclosure or a client crash.

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.

FreeRDP before 3.29.0 contains a client-side heap use-after-free in the async update message proxy for WINDOW_ICON_ORDER when AsyncUpdate is enabled (e.g. xfreerdp /async-update). In update_message_WindowIcon() a shallow CopyMemory() overwrites a freshly allocated lParam->iconInfo with the parser-owned windowIcon->iconInfo pointer. After the parser callback returns, update_recv_window_info_order() frees window_icon.iconInfo, but the queued async message still retains and later dispatches that stale pointer. A malicious or compromised RDP server sending a crafted RAIL Window Alternate Secondary Order with WINDOW_ORDER_ICON can trigger use-after-free, leading to memory corruption and client crash.

FreeRDP versions 3.28.0 and earlier contain a heap buffer overflow in the server-side RAIL channel handler (rail_server_handle_messages() in channels/rail/server/rail_main.c). When processing a RAIL PDU header, the code subtracts RAIL_PDU_HEADER_LENGTH from the peer-controlled orderLength field without first verifying orderLength is at least the header length. For orderLength values 0..3 this causes an unsigned integer underflow to a very large size, which bypasses the Stream_EnsureRemainingCapacity() capacity check (due to pointer arithmetic wraparound) and is then passed to WTSVirtualChannelRead(), resulting in an out-of-bounds heap write. A malicious or compromised RDP client can exploit this to corrupt the heap and crash the server. Fixed in FreeRDP 3.29.0.

FreeRDP before 3.29.0 fails to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can send oversized chunked response bodies to exhaust client memory resources without triggering the configured size limit.

FreeRDP before version 3.29.0 contains a denial of service vulnerability in the RDPEI server channel handler. A malicious RDP client can send a header-only RDPEI message with a large declared body length, causing excessive memory allocation on the server.

FreeRDP before 3.29.0 fails to properly validate server-supplied RDPDR paths in drive redirection, allowing attackers to access paths outside the configured shared root by sending non-rooted paths that bypass boundary checks.

FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate during client-side server TLS authentication. When server-purpose verification fails, the code falls back to client-purpose and any-purpose verification, allowing a certificate valid only for clientAuth to be accepted as the RDP server certificate.

FreeRDP before 3.29.0 contains an improper certificate hostname validation vulnerability. The TLS hostname matcher treats a wildcard pattern such as *.example.com as matching any hostname ending in .example.com, incorrectly accepting a wildcard certificate for multi-label subdomains like a.b.example.com.

FreeRDP before 3.29.0 contains a buffer over-disclosure vulnerability in the gateway WebSocket transport. The client's Pong reply reuses a fixed 1024-byte response stream whose length is not sealed to the actual received Ping payload, so a malicious peer causes an overlong Pong that discloses bytes beyond the received payload. A zero-length Ping triggers an assertion and terminates the client (denial of service).

FreeRDP before version 3.29.0 contains a heap out-of-bounds read vulnerability in glyph cache handling. A malicious RDP server can send a crafted fragment with an oversized declared size, causing a client crash.

FreeRDP before version 3.29.0 contains a heap out-of-bounds read vulnerability in the TSMF FFmpeg decoder when parsing AVC1 MPEG2VIDEOINFO media types with insufficient ExtraData. Attackers can trigger a crash by sending malformed media format data.

FreeRDP before version 3.29.0 contains a null pointer dereference vulnerability in smartcard cache request decoders. When smartcard emulation is enabled, attackers can send crafted requests with a NULL pointer, causing strlen() on NULL and client process termination.

FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser that fails to validate descriptor length before accessing the GUID field. A local attacker with a malicious USB video camera can trigger a heap read beyond allocated bounds during camera stream setup, causing denial of service.