Armin Novak

82 exploits Active since Nov 2018
CVE-2026-26955 WRITEUP HIGH WRITEUP
FreeRDP < 3.23.0 - Heap Buffer Overflow via GDI Surface Command ClearCodec
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 in xf_rail_window_common
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 - Denial of Service via Smartcard Read Size Alignment Bounds Check
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 - Denial of Service via Stream_EnsureCapacity
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 - Denial of Service via NTLM Authentication Module
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 - Use-After-Free in region.c
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 in HuffmanTree_makeFromFrequencies
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 - Denial of Service via 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 via Invalid Offset Validation
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 3.x < beta3 - Use-After-Free in RDPGFX_CMDID_RESETGRAPHICS Packet Processing
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
CVE-2023-40181 WRITEUP MEDIUM WRITEUP
FreeRDP < 2.11.0 - Integer Underflow in zgfx_decompress_segment
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. Affected versions are subject to an Integer-Underflow leading to Out-Of-Bound Read in the `zgfx_decompress_segment` function. In the context of `CopyMemory`, it's possible to read data beyond the transmitted packet range and likely 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 issue.
CVSS 5.3
CVE-2023-40186 WRITEUP MEDIUM WRITEUP
FreeRDP < 2.11.0 - Integer Overflow to Out-of-Bounds Write in gdi_CreateSurface
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.
CVSS 6.5
CVE-2023-40188 WRITEUP MEDIUM WRITEUP
FreeRDP < 2.11.0 - Out-of-Bounds Read in general_LumaToYUV444
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 Read in the `general_LumaToYUV444` function. This Out-Of-Bounds Read occurs because processing is done on the `in` variable without checking if it contains data of sufficient length. Insufficient data for the `in` variable may cause errors or crashes. 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.
CVSS 5.3
CVE-2023-40567 WRITEUP MEDIUM WRITEUP
FreeRDP <2.11.0, <3.0.0-beta3 - Memory Corruption
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.
CVSS 6.5
CVE-2023-40569 WRITEUP MEDIUM WRITEUP
FreeRDP <2.11.0, <3.0.0-beta3 - Buffer Overflow
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.
CVSS 6.5
CVE-2023-40574 WRITEUP MEDIUM WRITEUP
FreeRDP <3.0.0-beta3 - Buffer Overflow
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.
CVSS 6.5
CVE-2023-40575 WRITEUP MEDIUM WRITEUP
FreeRDP <3.0.0-beta3 - Memory Corruption
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 Read in the `general_YUV444ToRGB_8u_P3AC4R_BGRX` function. This issue is likely down to insufficient data for the `pSrc` variable and results in crashes. This issue has been addressed in version 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.
CVSS 5.3
CVE-2023-40576 WRITEUP MEDIUM WRITEUP
FreeRDP <3.0.0-beta3 - Memory Corruption
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 Read in the `RleDecompress` function. This Out-Of-Bounds Read occurs because FreeRDP processes the `pbSrcBuffer` variable without checking if it contains data of sufficient length. Insufficient data in the `pbSrcBuffer` variable may cause errors or crashes. This issue has been addressed in version 3.0.0-beta3. Users are advised to upgrade. There are no known workarounds for this issue.
CVSS 5.3
CVE-2023-40589 WRITEUP MEDIUM WRITEUP
FreeRDP <2.11.0,3.0.0-beta3 - Buffer Overflow
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions there is a Global-Buffer-Overflow in the ncrush_decompress function. Feeding crafted input into this function can trigger the overflow which has only been shown to 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 issue.
CVSS 4.3