Armin Novak

41 exploits Active since Nov 2018
CVE-2026-25941 WRITEUP MEDIUM WRITEUP
FreeRDP 2.x-3.x - Info Disclosure
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.
CVSS 4.3
CVE-2026-25942 WRITEUP HIGH WRITEUP
FreeRDP <3.23.0 - Memory Corruption
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.
CVSS 7.5
CVE-2026-25952 WRITEUP CRITICAL WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 9.8
CVE-2026-25953 WRITEUP CRITICAL WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 9.8
CVE-2026-25954 WRITEUP HIGH WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 7.5
CVE-2026-25955 WRITEUP CRITICAL WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 9.8
CVE-2026-25959 WRITEUP CRITICAL WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 9.8
CVE-2026-25997 WRITEUP CRITICAL WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 9.8
CVE-2026-26271 WRITEUP MEDIUM WRITEUP
FreeRDP <3.23.0 - Buffer Overflow
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a buffer overread in `freerdp_image_copy_from_icon_data()` (libfreerdp/codec/color.c) can be triggered by crafted RDP Window Icon (TS_ICON_INFO) data. The bug is reachable over the network when a client processes icon data from an RDP server (or from a man-in-the-middle). Version 3.23.0 fixes the issue.
CVSS 5.3
CVE-2026-26955 WRITEUP HIGH WRITEUP
FreeRDP <3.23.0 - Buffer Overflow
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.
CVSS 8.8
CVE-2026-26965 WRITEUP HIGH WRITEUP
FreeRDP <3.23.0 - Memory Corruption
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.
CVSS 8.8
CVE-2026-26986 WRITEUP HIGH WRITEUP
FreeRDP <3.23.0 - Use After Free
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.
CVSS 7.5
CVE-2026-27015 WRITEUP MEDIUM WRITEUP
FreeRDP <3.23.0 - DoS
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, a missing bounds check in `smartcard_unpack_read_size_align()` (`libfreerdp/utils/smartcard_pack.c:1703`) allows a malicious RDP server to crash the FreeRDP client via a reachable `WINPR_ASSERT` → `abort()`. The crash occurs in upstream builds where `WITH_VERBOSE_WINPR_ASSERT=ON` (default in FreeRDP 3.22.0 / current WinPR CMake defaults). Smartcard redirection must be explicitly enabled by the user (e.g., `xfreerdp /smartcard`; `/smartcard-logon` implies `/smartcard`). Version 3.23.0 fixes the issue.
CVSS 6.5
CVE-2026-27951 WRITEUP MEDIUM WRITEUP
FreeRDP <3.23.0 - DoS
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the function `Stream_EnsureCapacity` can create an endless blocking loop. This may affect all client and server implementations using `FreeRDP`. For practical exploitation this will only work on 32bit systems where the available physical memory is `>= SIZE_MAX`. Version 3.23.0 contains a patch. No known workarounds are available.
CVSS 5.3
CVE-2018-8784 WRITEUP CRITICAL WRITEUP
FreeRDP <2.0.0-rc4 - Buffer Overflow
FreeRDP prior to version 2.0.0-rc4 contains a Heap-Based Buffer Overflow in function zgfx_decompress_segment() that results in a memory corruption and probably even a remote code execution.
CVSS 9.8
CVE-2018-8785 WRITEUP CRITICAL WRITEUP
FreeRDP <2.0.0-rc4 - Buffer Overflow
FreeRDP prior to version 2.0.0-rc4 contains a Heap-Based Buffer Overflow in function zgfx_decompress() that results in a memory corruption and probably even a remote code execution.
CVSS 9.8
CVE-2018-8786 WRITEUP CRITICAL WRITEUP
FreeRDP <2.0.0-rc4 - Memory Corruption
FreeRDP prior to version 2.0.0-rc4 contains an Integer Truncation that leads to a Heap-Based Buffer Overflow in function update_read_bitmap_update() and results in a memory corruption and probably even a remote code execution.
CVSS 9.8
CVE-2018-8787 WRITEUP CRITICAL WRITEUP
FreeRDP <2.0.0-rc4 - Memory Corruption
FreeRDP prior to version 2.0.0-rc4 contains an Integer Overflow that leads to a Heap-Based Buffer Overflow in function gdi_Bitmap_Decompress() and results in a memory corruption and probably even a remote code execution.
CVSS 9.8
CVE-2018-8788 WRITEUP CRITICAL WRITEUP
FreeRDP <2.0.0-rc4 - Memory Corruption
FreeRDP prior to version 2.0.0-rc4 contains an Out-Of-Bounds Write of up to 4 bytes in function nsc_rle_decode() that results in a memory corruption and possibly even a remote code execution.
CVSS 9.8
CVE-2018-8789 WRITEUP HIGH WRITEUP
FreeRDP <2.0.0-rc4 - DoS
FreeRDP prior to version 2.0.0-rc4 contains several Out-Of-Bounds Reads in the NTLM Authentication module that results in a Denial of Service (segfault).
CVSS 7.5
CVE-2019-17177 WRITEUP HIGH WRITEUP
Freerdp < 1.0.2 - Memory Leak
libfreerdp/codec/region.c in FreeRDP through 1.1.x and 2.x through 2.0.0-rc4 has memory leaks because a supplied realloc pointer (i.e., the first argument to realloc) is also used for a realloc return value.
CVSS 7.5
CVE-2019-17178 WRITEUP HIGH WRITEUP
Freerdp < 1.0.2 - Memory Leak
HuffmanTree_makeFromFrequencies in lodepng.c in LodePNG through 2019-09-28, as used in WinPR in FreeRDP and other products, has a memory leak because a supplied realloc pointer (i.e., the first argument to realloc) is also used for a realloc return value.
CVSS 7.5
CVE-2023-39350 WRITEUP MEDIUM WRITEUP
Freerdp < 2.11.0 - Integer Underflow
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. This issue affects Clients only. Integer underflow leading to DOS (e.g. abort due to `WINPR_ASSERT` with default compilation flags). When an insufficient blockLen is provided, and proper length validation is not performed, an Integer Underflow occurs, leading to a Denial of Service (DOS) vulnerability. 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.
CVSS 5.9
CVE-2023-39352 WRITEUP MEDIUM WRITEUP
Freerdp < 2.11.0 - Out-of-Bounds Write
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.
CVSS 5.3
CVE-2023-39355 WRITEUP HIGH WRITEUP
Freerdp - Use After Free
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.
CVSS 7.0