FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP's winpr/libwinpr/sspi/Kerberos/kerberos.c kerberos_DecryptMessage function fails to bound the peer-controlled GSS Wrap-token EC field before using it with RRC in IOV pointer offsets, allowing a malicious RDP peer to trigger out-of-bounds reads and in-place writes during CredSSP/NLA Kerberos decryption. This issue is fixed in version 3.30.0.

FreeRDP before 3.30.0 contains a server-side authentication bypass in the RDSTLS handshake. When a server is configured with RdstlsSecurity = TRUE, the handshake dispatches inbound PDUs based solely on the attacker-supplied wire pduType without verifying that the received PDU is the one required at the current step. Because the rdpRdstls object is calloc-zeroed, its resultCode defaults to 0 (RDSTLS_RESULT_SUCCESS). An unauthenticated remote client can send a Capabilities PDU instead of the required Authentication Request PDU; rdstls_process_capabilities() returns success without ever setting resultCode, so the server responds with an AUTHRSP carrying resultCode SUCCESS and treats the session as authenticated without evaluating any password, redirection GUID, or auto-reconnect cookie. This affects the released FreeRDP 3.x series (e.g., 3.27.1) and master HEAD; at the time of the advisory no patched version was available.

FreeRDP before 3.30.0 contains an out-of-bounds vulnerability in kerberos_DecryptMessage() (winpr/libwinpr/sspi/Kerberos/kerberos.c). The 16-bit EC (extra count) field of a peer-supplied GSS Wrap token (RFC 4121) is used directly in pointer arithmetic to locate the encrypted regions without being bounds-checked, while only RRC and the total buffer length are validated. A malicious peer (server or client) can supply a large EC value (up to 0xFFFF) during CredSSP/NLA authentication, moving the decrypt operation's base pointers past the end of the ~60-byte token buffer. Because the AES-CTS-HMAC enctypes decrypt in place before the HMAC integrity check, this results in an out-of-bounds read and in-place out-of-bounds write, potentially leading to information disclosure, memory corruption, or denial of service.

FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.30.0, FreeRDP server-side RDSTLS in libfreerdp/core/rdstls.c accepts an attacker-supplied RDSTLS_TYPE_CAPABILITIES PDU while rdstls_server_authenticate is waiting for RDSTLS_TYPE_AUTHREQ, leaving resultCode at RDSTLS_RESULT_SUCCESS and allowing a remote unauthenticated client to bypass the RedirectionGuid, username, domain, or password checks. This issue is fixed in version 3.30.0.

FreeRDP before 3.29.0 contains integer overflow vulnerabilities in the audio input redirection channel (audin) across ALSA, sndio, WinMM, and OpenSL ES backends that fail to validate the FramesPerPacket parameter from RDP servers. Attackers can supply a malicious FramesPerPacket value causing allocation size wraparound, resulting in heap-based buffer overflow on ALSA or denial of service on all platforms.

FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows clipboard client's CliprdrStream_Read function (client/Windows/wf_cliprdr.c). When an OLE paste consumer (e.g. explorer.exe) calls IStream::Read with a fixed-size buffer of cb bytes, CliprdrStream_Read requests file contents from the RDP server and then copies the response into the caller's buffer using the server-supplied length (req_fsize) instead of cb. A malicious or compromised RDP server can return an oversized CB_FILECONTENTS_RESPONSE, causing an out-of-bounds write of attacker-controlled data into the paste consumer's heap buffer when a user pastes server-offered clipboard file contents.

FreeRDP Windows client before 3.29.0 contains a heap buffer overflow vulnerability in the clipboard virtual channel when processing CLIPRDR_FILE_CONTENTS_RESPONSE PDUs without validating the server-provided size against the destination buffer. A malicious RDP server can send a response with a data payload significantly larger than requested, causing arbitrary heap memory corruption that may enable remote code execution when a user performs a paste operation.

FreeRDP before 3.29.0 contains client-side heap use-after-free vulnerabilities in the async update message proxy for RAIL WINDOW_STATE_ORDER and NOTIFY_ICON_STATE_ORDER when AsyncUpdate is enabled. When a malicious or compromised RDP server sends crafted update orders, the message proxy shallow-copies structures containing nested parser-owned pointers (e.g., titleInfo.string, windowRects, visibilityRects, icon buffers). The parser frees those nested buffers after the callback returns, so the queued async message later dispatches stale pointers, potentially causing memory corruption or a client crash.

FreeRDP before 3.29.0 fails to enforce the RESPONSE_SIZE_LIMIT when processing Transfer-Encoding: chunked HTTP responses in http_response_recv_body(). Attackers controlling a malicious RD Gateway endpoint can send oversized chunked response bodies to exhaust client memory resources without triggering the configured size limit.

FreeRDP before 3.29.0 contains an out-of-bounds heap read vulnerability in the UVC H.264 extension-unit parser that fails to validate descriptor length before accessing the GUID field. A local attacker with a malicious USB video camera can trigger a heap read beyond allocated bounds during camera stream setup, causing denial of service.