freerdp3 vulnerabilities · Page 7

FreeRDP before 3.29.0 Heap Out-of-Bounds Read via TSMF

FreeRDP before 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 send malformed media format data from a server to trigger a crash by reading fixed offsets without validating source buffer length.

FreeRDP RDP File Parser Remote Code Execution via CLI Options

FreeRDP before 3.28.0 treats lines beginning with forward slash in RDP files as raw command-line options, exposing the entire CLI parser surface to untrusted files. Attackers can craft malicious RDP files with /rdp2tcp, /cert:ignore, or /drive options to execute arbitrary commands, bypass certificate validation, or expose local filesystems without user interaction.

FreeRDP before 3.28.0 Double-Free via selectedmonitors

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 (xfre

FreeRDP before 3.28.0 Heap Buffer Overflow via crypto_rsa_common

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 b

FreeRDP: Integer overflow leading to heap buffer overflow in Orders Delta Points parsing

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.

Out-of-bounds read in the camera device enumerator server (rdpecam) via unterminated DeviceName / VirtualChannelName

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, FreeRDP server implementations with the MS-RDPECAM camera device enumerator channel enabled scan attacker-supplied DeviceName and VirtualChannelName fields for a NUL terminator in channels/rdpecam/server/camera_device_enumerator_main.c and then dereference once past the scan bound, allowing a malicious RDP client to trigger a 1- to 2-byte out-of-bounds heap read. This issue is fixed in version 3.28.0.

FreeRDP planar_decompress_plane_rle_only: heap OOB read — incomplete fix for CVE-2026-23530

FreeRDP is a free implementation of the Remote Desktop Protocol. From 3.21.0 before 3.28.0, FreeRDP clients using the GFX pipeline contain an incomplete fix for CVE-2026-23530 in planar_decompress_plane_rle_only in libfreerdp/codec/planar.c, allowing a malicious RDP server to send a truncated RDPGFX_CMDID_WIRETOSURFACE_1 planar payload that reads one byte past the input buffer. This issue is fixed in version 3.28.0.

FreeRDP: Heap out-of-bounds write in RemoteFX (RFX) Cache Bitmap V3 decode

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.27.1, FreeRDP clients launched with the non-default /cache:codec:rfx option pass desktop stride and height to RemoteFX decoding for Cache Bitmap V3 data while allocating bitmap->data only for the smaller DstWidth and DstHeight in gdi_Bitmap_Decompress, allowing a malicious RDP server to trigger a heap out-of-bounds write with attacker-controlled offset and content. This issue is fixed in version 3.27.1.

FreeRDP - Use-After-Free via Race Condition in DRDYNVC Channel Callback

FreeRDP before 3.22.0 contains a use-after-free vulnerability in dvcman_channel_close and dvcman_call_on_receive due to improper synchronization of channel_callback access. A malicious RDP server can trigger a race condition by sending DYNVC_DATA and DYNVC_CLOSE messages concurrently, causing heap-use-after-free in the drdynvc client thread and potentially enabling remote code execution or denial of service.

Heap-buffer-overflow write in planar bitmap decoder

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 cliprdr server heap-buffer-overflow via undersized capabilitySetLength in CB_CLIP_CAPS

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP client can trigger a heap-buffer-overflow write in FreeRDP's server-side clipboard (cliprdr) channel by sending a CB_CLIP_CAPS PDU with a too-small capabilitySetLength. This can crash the server process (remote DoS) and may be exploitable for code execution because it corrupts heap memory. This vulnerability is fixed in 3.26.0.

FreeRDP RDPEAR NDR ref-id aliasing causes client-side UAF/double-free and type confusion

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, FreeRDP's RDPEAR NDR parser accepts one non-null NDR pointer ref-id for multiple logical pointer fields without tracking the pointed object's expected NDR type or ownership. When the same ref-id is reused across two pointer fields, the parser assigns the same heap object to both output fields. The generic destructor later walks each field independently and destroys/frees both pointers. This causes a malicious-server-triggerable heap use-after-free / double-free in the FreeRDP client's RDPEAR authentication-redirection path. This vulnerability is fixed in 3.26.0.

FreeRDP RDPGFX CacheToSurface heap-buffer-overflow via clamped-rectangle validation bypass

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.26.0, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client by sending crafted RDPGFX PDUs. The bug is in gdi_CacheToSurface: it validates a destination rectangle that is clamped to UINT16_MAX, but then performs the copy using the original cacheEntry->width/height. This can cause a large out-of-bounds heap write and may lead to client crashes or code execution. This bug is reachable from a malicious RDP server, but only when the client has RDPGFX enabled. This vulnerability is fixed in 3.26.0.

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.

FreeRDP: contains_dotdot() off-by-one allows drive channel path traversal via terminal ..

FreeRDP is a free implementation of the Remote Desktop Protocol. Versions prior to 3.25.0 have an off-by-one in the path traversal filter in `channels/drive/client/drive_file.c`. The `contains_dotdot()` function catches `../` and `..\` mid-path but misses `..` when it's the last component with no trailing separator. A rogue RDP server can read, list, or write files one directory above the client's shared folder through RDPDR requests. This requires the victim to connect with drive redirection enabled. Version 3.25.0 patches the issue.

• Update to 3.15.0+dfsg-2.1+deb13u3

FreeRDP: Possible double free in kerberos_AcceptSecurityContext

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, a double-free vulnerability in kerberos_AcceptSecurityContext() and kerberos_InitializeSecurityContextA() (WinPR, winpr/libwinpr/sspi/Kerberos/kerberos.c) can cause a crash in any FreeRDP clients on systems where Kerberos and/or Kerberos U2U is configured (Samba AD member, or krb5 for NFS). The crash is triggered during NLA connection teardown and requires a failed authentication attempt. This issue has been patched in version 3.24.2.

• Update to 3.15.0+dfsg-2.1+deb13u2

FreeRDP: Persistent Cache bmpSize Desync - Heap OOB Write

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in persistent_cache_read_entry_v3() in libfreerdp/cache/persistent.c, persistent->bmpSize is updated before winpr_aligned_recalloc(). If realloc fails, bmpSize is inflated while bmpData points to the old buffer. This issue has been patched in version 3.24.2.

• Update to 3.15.0+dfsg-2.1+deb13u2

FreeRDP: H.264 YUV Buffer Dimension Desync - Heap OOB Write

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in yuv_ensure_buffer() in libfreerdp/codec/h264.c, h264->width and h264->height are updated before the reallocation loop. If any winpr_aligned_recalloc() call fails, the function returns FALSE but width/height are already inflated. This issue has been patched in version 3.24.2.

• Update to 3.15.0+dfsg-2.1+deb13u2

FreeRDP: ClearCodec Glyph Cache Count Desync - Heap OOB Read

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, pixel data from adjacent heap memory is rendered to screen, potentially leaking sensitive data to the attacker. This issue has been patched in version 3.24.2.

• Update to 3.15.0+dfsg-2.1+deb13u2

FreeRDP: ClearCodec resize_vbar_entry() Heap OOB Write

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.24.2, in resize_vbar_entry() in libfreerdp/codec/clear.c, vBarEntry->size is updated to vBarEntry->count before the winpr_aligned_recalloc() call. If realloc fails, size is inflated while pixels still points to the old, smaller buffer. On a subsequent call where count <= size (the inflated value), realloc is skipped. The caller then writes count * bpp bytes of attacker-controlled pixel data into the undersized buffer, causing a heap buffer overflow. This issue has been patched in version 3.24.2.

• Update to 3.15.0+dfsg-2.1+deb13u2