Armin Novak

82 exploits Active since Nov 2018
CVE-2026-40033 WRITEUP HIGH WRITEUP
FreeRDP - Heap-buffer-overflow in gdi_CacheToSurface via rectangle validation bypass
FreeRDP before 3.26.0 contains a heap-buffer-overflow vulnerability in gdi_CacheToSurface that allows remote attackers to write out-of-bounds heap memory. The vulnerability occurs because rectangle validation clamps coordinates to UINT16_MAX but performs copy operations using unclamped cache entry dimensions, enabling malicious RDP servers to trigger large out-of-bounds writes and potentially achieve remote code execution or client crash.
CVSS 8.8
CVE-2023-39356 WRITEUP MEDIUM WRITEUP
FreeRDP < 2.11.0 - Out-of-Bounds Read in gdi_multi_opaque_rect
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions a missing offset validation may lead to an Out Of Bound Read in the function `gdi_multi_opaque_rect`. In particular there is no code to validate if the value `multi_opaque_rect->numRectangles` is less than 45. Looping through `multi_opaque_rect->`numRectangles without proper boundary checks can lead to Out-of-Bounds Read errors which will likely lead to 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-2023-39356 WRITEUP MEDIUM WRITEUP
FreeRDP < 2.11.0 - Out-of-Bounds Read in gdi_multi_opaque_rect
FreeRDP is a free implementation of the Remote Desktop Protocol (RDP), released under the Apache license. In affected versions a missing offset validation may lead to an Out Of Bound Read in the function `gdi_multi_opaque_rect`. In particular there is no code to validate if the value `multi_opaque_rect->numRectangles` is less than 45. Looping through `multi_opaque_rect->`numRectangles without proper boundary checks can lead to Out-of-Bounds Read errors which will likely lead to 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-2023-40181 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-2023-40567 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-2024-22211 WRITEUP LOW WRITEUP
FreeRDP < 2.11.5 - Heap-Buffer Overflow via RDPGFX_RESET_GRAPHICS_PDU
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.
CVSS 3.7
CVE-2026-25952 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_SetWindowMinMaxInfo
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-2026-25952 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_SetWindowMinMaxInfo
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 in xf_rail Window Handling
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-2026-25952 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_SetWindowMinMaxInfo
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 in xf_rail Window Handling
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-2026-25952 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_SetWindowMinMaxInfo
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 in xf_rail Window Handling
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-2026-25953 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_rail Window Handling
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-2026-25953 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_rail Window Handling
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-2026-25955 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_AppUpdateWindowFromSurface
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-2026-25955 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_AppUpdateWindowFromSurface
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-2026-25942 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-2026-25955 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_AppUpdateWindowFromSurface
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-2026-27950 WRITEUP HIGH WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in SDL2 Pointer Implementation
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the fix for the heap-use-after-free described in CVE-2026-24680 is incomplete. While the vulnerable execution flow referenced in the advisory exists in the SDL2 implementation, the fix appears to have been applied only to the SDL3 code path. In the SDL2 implementation, the pointer is not nulled after free. This creates a situation where the advisory suggests the vulnerability is fully resolved, while builds or environments still using SDL2 may retain the vulnerable logic. A complete fix is available in version 3.23.0.
CVSS 7.5
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-2026-25955 WRITEUP CRITICAL WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in xf_AppUpdateWindowFromSurface
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-2026-27950 WRITEUP HIGH WRITEUP
FreeRDP < 3.23.0 - Use-After-Free in SDL2 Pointer Implementation
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, the fix for the heap-use-after-free described in CVE-2026-24680 is incomplete. While the vulnerable execution flow referenced in the advisory exists in the SDL2 implementation, the fix appears to have been applied only to the SDL3 code path. In the SDL2 implementation, the pointer is not nulled after free. This creates a situation where the advisory suggests the vulnerability is fully resolved, while builds or environments still using SDL2 may retain the vulnerable logic. A complete fix is available in version 3.23.0.
CVSS 7.5
CVE-2026-31884 WRITEUP MEDIUM WRITEUP
FreeRDP < 3.24.0 - Denial of Service via Division by Zero in ADPCM Decoders
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.24.0, division by zero in MS-ADPCM and IMA-ADPCM decoders when nBlockAlign is 0, leading to a crash. In libfreerdp/codec/dsp.c, both ADPCM decoders use size % block_size where block_size = context->common.format.nBlockAlign. The nBlockAlign value comes from the Server Audio Formats PDU on the RDPSND channel. The value 0 is not validated anywhere before reaching the decoder. When nBlockAlign = 0, the modulo operation causes a SIGFPE (floating point exception) crash. This vulnerability is fixed in 3.24.0.
CVSS 6.5
CVE-2026-33952 WRITEUP MEDIUM WRITEUP
FreeRDP: DoS via WINPR_ASSERT in rts_read_auth_verifier_no_checks
FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, an unvalidated auth_length field read from the network triggers a WINPR_ASSERT() failure in rts_read_auth_verifier_no_checks(), causing any FreeRDP client connecting through a malicious RDP Gateway to crash with SIGABRT. This is a pre-authentication denial of service affecting all FreeRDP clients using RPC-over-HTTP gateway transport. The assertion is active in default release builds (WITH_VERBOSE_WINPR_ASSERT=ON). This issue has been patched in version 3.24.2.
CVSS 6.5