FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation vulnerability. The TLS hostname matcher (tls_match_hostname() in libfreerdp/crypto/tls.c) treats a wildcard pattern such as *.example.com as matching any hostname ending in .example.com, so it incorrectly accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's X509_check_host() rejects). This weakens TLS server authentication under wildcard-certificate conditions.

FreeRDP before 3.29.0 improperly validates the Extended Key Usage (EKU) purpose of the peer certificate during client-side server TLS authentication. In x509_utils_verify(), when server-purpose (X509_PURPOSE_SSL_SERVER) verification fails, the code falls back to client-purpose and any-purpose verification, so a trusted, hostname-matching certificate valid only for clientAuth can be accepted as the RDP server certificate. In environments relying on EKU separation between client and server certificates, this allows a clientAuth-only certificate issued by a trusted CA to bypass server certificate purpose validation.

FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the server-controlled RDP redirection TargetNetAddress field. This value is copied into the client's ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy CONNECT request line and Host header by http_proxy_connect() without filtering. A malicious or compromised RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary headers/requests into the HTTP proxy CONNECT request.

FreeRDP before 3.29.0 contains a buffer over-disclosure vulnerability in the gateway WebSocket transport (libfreerdp/core/gateway/websocket.c). 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 gateway/WebSocket peer sending a non-empty Ping control frame causes the client to reply with an overlong Pong that discloses bytes beyond the received payload (the peer receives the masking key and can unmask the reply). A zero-length Ping reaches an assertion and terminates the client (denial of service).

FreeRDP before 3.28.0 (affected 3.x through 3.27.1) contains a double-free vulnerability in freerdp_client_rdp_file_apply_to_settings() (client/common/file.c) when parsing the selectedmonitors field of a .rdp connection file. The MonitorIds array is allocated through the settings object, and a raw non-owning pointer to it is freed on the strtoul error path without clearing settings->MonitorIds, leaving it dangling; at teardown freerdp_settings_free() frees the same buffer again. An attacker who convinces a victim to open a crafted .rdp file with oversized monitor tokens can trigger a size-controlled double-free in any FreeRDP CLI client (xfreerdp/sdl-freerdp/wlfreerdp) in the default configuration.

FreeRDP before 3.28.0 (affected <=3.27.1) contains a heap-based buffer overflow in crypto_rsa_common() (libfreerdp/crypto/crypto.c). The function writes the modular-exponentiation result into the caller's output buffer via BN_bn2bin() and only afterward checks output_length > out_length, so out-of-bounds bytes are written before the bounds check. On the server side, when a client selects RDP Standard Security, the encrypted client random is decrypted into a fixed 32-byte buffer. Because the server publishes its RSA public key, an unauthenticated attacker can forge a ciphertext whose decrypted value is up to the full modulus length (e.g. 256 bytes for RSA-2048), overflowing the 32-byte heap buffer by up to ~224 attacker-controlled bytes pre-authentication, resulting in denial of service.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, a size_t underflow in the IMA-ADPCM and MS-ADPCM audio decoders leads to heap-buffer-overflow write via the RDPSND audio channel. In libfreerdp/codec/dsp.c, the IMA-ADPCM and MS-ADPCM decoders subtract block header sizes from a size_t variable without checking for underflow. When nBlockAlign (received from the server) is set such that size % block_size == 0 triggers the header parsing at a point where size is smaller than the header (4 or 8 bytes), the subtraction wraps size to ~SIZE_MAX. The while (size > 0) loop then continues for an astronomical number of iterations. This vulnerability is fixed in 3.24.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0 on 32-bit builds, FreeRDP clients contain an integer overflow in update_read_delta_points in libfreerdp/core/orders.c when multiplying an attacker-controlled point count by sizeof(DELTA_POINT), allowing a malicious RDP peer to allocate an undersized heap buffer and then write beyond it during initialization. This issue is fixed in version 3.28.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's planar bitmap decoder has an out-of-bounds heap write when decoding RLE planar data. In libfreerdp/codec/planar.c, freerdp_bitmap_decompress_planar() validates the X destination coordinate nXDst against the caller-provided destination stride (nDstStep) even when it is writing into the internal temp buffer pTempData. An attacker can bypass the check with a large nDstStep and a large nXDst, causing planar_decompress_plane_rle() to write past the end of pTempData. This vulnerability is fixed in 3.26.0.

FreeRDP is a set of free and open source remote desktop protocol library and clients. In affected versions an integer overflow in `freerdp_bitmap_planar_context_reset` leads to heap-buffer overflow. This affects FreeRDP based clients. FreeRDP based server implementations and proxy are not affected. A malicious server could prepare a `RDPGFX_RESET_GRAPHICS_PDU` to allocate too small buffers, possibly triggering later out of bound read/write. Data extraction over network is not possible, the buffers are used to display an image. This issue has been addressed in version 2.11.5 and 3.2.0. Users are advised to upgrade. there are no know workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients that use a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulnerable to out-of-bounds read. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, use `/gfx` or `/rfx` modes (on by default, require server side support).

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients that use a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulnerable to out-of-bounds read. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, deactivate `/gfx` (on by default, set `/bpp` or `/rfx` options instead.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients and servers that use a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulnerable to out-of-bounds read. Versions 3.5.0 and 2.11.6 patch the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read. This occurs when `WCHAR` string is read with twice the size it has and converted to `UTF-8`, `base64` decoded. The string is only used to compare against the redirection server certificate. Version 3.5.1 contains a patch for the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients using a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulnerable to integer overflow and out-of-bounds write. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, do not use `/gfx` options (e.g. deactivate with `/bpp:32` or `/rfx` as it is on by default).

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read if `((nWidth == 0) and (nHeight == 0))`. Version 3.5.1 contains a patch for the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based based clients using `/bpp:32` legacy `GDI` drawing path with a version of FreeRDP prior to 3.5.0 or 2.11.6 are vulnerable to out-of-bounds read. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, use modern drawing paths (e.g. `/rfx` or `/gfx` options). The workaround requires server side support.

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients that use a version of FreeRDP prior to 3.5.0 or 2.11.6 and have connections to servers using the `NSC` codec are vulnerable to integer underflow. Versions 3.5.0 and 2.11.6 patch the issue. As a workaround, do not use the NSC codec (e.g. use `-nsc`).

FreeRDP is a free implementation of the Remote Desktop Protocol. FreeRDP based clients prior to version 3.5.1 are vulnerable to out-of-bounds read. Version 3.5.1 contains a patch for the issue. No known workarounds are available.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, the gdi_surface_bits() function processes SURFACE_BITS_COMMAND messages sent by the RDP server. When the command is handled using NSCodec, the bmp.width and bmp.height values provided by the server are not properly validated against the actual desktop dimensions. A malicious RDP server can supply crafted bmp.width and bmp.height values that exceed the expected surface size. Because these values are used during bitmap decoding and memory operations without proper bounds checking, this can lead to a heap buffer overflow. Since the attacker can also control the associated pixel data transmitted by the server, the overflow may be exploitable to overwrite adjacent heap memory. This vulnerability is fixed in 3.24.0.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_cliprdr_provide_data_` passes freed `pDstData` to `XChangeProperty` because the cliprdr channel thread calls `xf_cliprdr_server_format_data_response` which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls `xf_cliprdr_clear_cached_data` → `HashTable_Clear` which frees the same data via `xf_cached_data_free`, triggering a heap use after free. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_clipboard_format_equal` reads freed `lastSentFormats` memory because `xf_clipboard_formats_free` (called from the cliprdr channel thread during auto-reconnect) frees the array while the X11 event thread concurrently iterates it in `xf_clipboard_changed`, triggering a heap use after free. Version 3.23.0 fixes the issue.

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.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_SetWindowMinMaxInfo` dereferences a freed `xfAppWindow` pointer because `xf_rail_get_window` in `xf_rail_server_min_max_info` 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 3.21.0, in ClearCodec, when `glyphData` is present, `clear_decompress` calls `freerdp_image_copy_no_overlap` without validating the destination rectangle, allowing an out-of-bounds read/write via crafted RDPGFX surface updates. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0,`freerdp_bitmap_decompress_planar` does not validate `nSrcWidth`/`nSrcHeight` against `planar->maxWidth`/`maxHeight` before RLE decode. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, offscreen bitmap deletion leaves `gdi->drawing` pointing to freed memory, causing UAF when related update packets arrive. A malicious server can trigger a client‑side use after free, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the RDPGFX ClearCodec decode path when maliciously crafted residual data causes out-of-bounds writes during color output. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the ClearCodec bands decode path when crafted band coordinates allow writes past the end of the destination surface buffer. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap use-after-free occurs in irp_thread_func because the IRP is freed by irp->Complete() and then accessed again on the error path. This vulnerability is fixed in 3.20.1.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, `xf_AppUpdateWindowFromSurface` reads from a freed `xfAppWindow` because the RDPGFX DVC thread obtains a bare pointer via `xf_rail_get_window` without any lifetime protection, while the main thread can concurrently delete the window through a fastpath window-delete order. Version 3.23.0 fixes the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Out-Of-Bounds Write in the `clear_decompress_bands_data` function in which there is no offset validation. Abuse of this vulnerability may lead to an out of bounds write. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. there are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an IntegerOverflow leading to Out-Of-Bound Write Vulnerability in the `gdi_CreateSurface` function. This issue affects FreeRDP based clients only. FreeRDP proxies are not affected as image decoding is not done by a proxy. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions of the 3.x beta branch are subject to a Use-After-Free issue in the `avc420_ensure_buffer` and `avc444_ensure_buffer` functions. If the value of `piDstSize[x]` is 0, `ppYUVDstData[x]` will be freed. However, in this case `ppYUVDstData[x]` will not have been updated which leads to a Use-After-Free vulnerability. This issue has been addressed in version 3.0.0-beta3. Users of the 3.x beta releases are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Out-Of-Bounds Write in the `writePixelBGRX` function. This issue is likely down to incorrect calculations of the `nHeight` and `srcStep` variables. This issue has been addressed in version 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Out-Of-Bounds Write in the `progressive_decompress` function. This issue is likely down to incorrect calculations of the `nXSrc` and `nYSrc` variables. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. there are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an invalid offset validation leading to Out Of Bound Write. This can be triggered when the values `rect->left` and `rect->top` are exactly equal to `surface->width` and `surface->height`. eg. `rect->left` == `surface->width` && `rect->top` == `surface->height`. In practice this should cause a crash. This issue has been addressed in versions 2.11.0 and 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, a client-side heap buffer overflow occurs in the FreeRDP client’s `gdi_SurfaceToSurface` path due to a mismatch between destination rectangle clamping and the actual copy size. A malicious server can trigger a client‑side heap buffer overflow, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Versions of FreeRDP on the 3.x release branch before beta3 are subject to a Use-After-Free in processing `RDPGFX_CMDID_RESETGRAPHICS` packets. If `context->maxPlaneSize` is 0, `context->planesBuffer` will be freed. However, without updating `context->planesBuffer`, this leads to a Use-After-Free exploit vector. In most environments this should only result in a crash. This issue has been addressed in version 3.0.0-beta3 and users of the beta 3.x releases are advised to upgrade. There are no known workarounds for this vulnerability.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.21.0, `xf_Pointer_New` frees `cursorPixels` on failure, then `pointer_free` calls `xf_Pointer_Free` and frees it again, triggering ASan UAF. A malicious server can trigger a client‑side use after free, causing a crash (DoS) and potential heap corruption with code‑execution risk depending on allocator behavior and surrounding heap layout. Version 3.21.0 contains a patch for the issue.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a heap-buffer-overflow occurs in drive read when a server-controlled read length is used to read file data into an IRP output stream buffer without a hard upper bound, allowing an oversized read to overwrite heap memory. This vulnerability is fixed in 3.20.1.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, RDPEAR’s NDR array reader does not perform bounds checking on the on‑wire element count and can write past the heap buffer allocated from hints, causing a heap buffer overflow in ndr_read_uint8Array. This vulnerability is fixed in 3.20.1.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client when processing Audio Input (AUDIN) format lists. audin_process_formats reuses callback->formats_count across multiple MSG_SNDIN_FORMATS PDUs and writes past the newly allocated formats array, causing memory corruption and a crash. This vulnerability is fixed in 3.20.1.

FreeRDP is a free implementation of the Remote Desktop Protocol (RDP). Prior to version 2.7.0, server side authentication against a `SAM` file might be successful for invalid credentials if the server has configured an invalid `SAM` file path. FreeRDP based clients are not affected. RDP server implementations using FreeRDP to authenticate against a `SAM` file are affected. Version 2.7.0 contains a fix for this issue. As a workaround, use custom authentication via `HashCallback` and/or ensure the `SAM` database path configured is valid and the application has file handles left.

An exploitable denial of service vulnerability exists within the reading of proprietary server certificates in FreeRDP 2.0.0-beta1+android11. A specially crafted challenge packet can cause the program termination leading to a denial of service condition. An attacker can compromise the server or use man in the middle to trigger this vulnerability.

Microsoft Defender for IoT Remote Code Execution Vulnerability

In gnss service, there is a possible escalation of privilege due to improper certificate validation. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS08720039; Issue ID: MSV-1424.

The EU Technical Specifications for Digital COVID Certificates before 1.1 mishandle certificate governance. A non-production public key certificate could have been used in production.

An improper certificate validation vulnerability exists in ToDesktop Builder v0.32.1 This vulnerability allows an unauthenticated, on-path attacker to spoof backend responses by exploiting insufficient certificate validation.

If a user visited a webpage with an invalid TLS certificate, and granted an exception, the webpage was able to provide a WebAuthn challenge that the user would be prompted to complete. This is in violation of the WebAuthN spec which requires "a secure transport established without errors". This vulnerability was fixed in Firefox 140 and Thunderbird 140.