CVE-2026-57157

The FreeRDP client 3.0.0 before 3.32.0 does not check a server-selected PROTOCOL_RDSTLS or PROTOCOL_HYBRID_EX against its enabled protocol set in nego_process_negotiation_response(), allowing a security protocol downgrade. A malicious server or man-in-the-middle can select RDSTLS to override /sec:nla pinning, complete authentication with an all-zero cookie, and receive the user's cleartext password in the Client Info PDU.

FreeRDP 3.17.1 before 3.32.0 contains a heap buffer over-read vulnerability in DynvcTrackerHandleCreateBack of the freerdp-proxy DRDYNVC channel handler that allows malicious backend RDP servers to read heap memory out of bounds. Attackers can send a CREATE_REQUEST_PDU whose channel name lacks a NUL byte, causing an unbounded snprintf read that leaks memory into proxy logs or crashes the process.

FreeRDP from 3.0.0 before 3.32.0 contains a heap out-of-bounds read vulnerability. A malicious RD Gateway can set MsgBytes far larger than the NDR string ActualCount in consent or service messages, causing UTF-8 conversion to read past the stream allocation and crash the client.

FreeRDP from 3.20.1 before 3.32.0 contains an uncontrolled resource allocation vulnerability. A malicious RDP server can send IRP_MJ_READ with Length 0xffffffff, causing roughly 4 GiB of zeroed allocation on 64-bit builds or an under-reserved buffer on 32-bit builds.

FreeRDP 3.11.0 before 3.32.0 does not validate that AVC444 and AVC444v2 region widths are even before YUV444 conversion, so an odd width reaches an assertion and aborts the client. A malicious or compromised RDP server can terminate a connected FreeRDP client after RDPGFX AVC444 negotiation by sending an in-bounds region rectangle with an odd width.

FreeRDP 3.0.0 before 3.32.0 contains a heap use-after-free vulnerability in smartcard emulation when SCARD_IOCTL_DISCONNECT and SCARD_IOCTL_TRANSMIT operate concurrently on one card handle. A malicious RDP server can overlap these IRPs through separate context workers to free and reuse the SCardHandle, causing client-process heap corruption and termination.

FreeRDP 2.3.0 before 3.32.0 dereferences a NULL stream in rdg_process_close_packet in libfreerdp/core/gateway/rdg.c because rdg_process_control_packet accepts a header-only PKT_TYPE_CLOSE_CHANNEL packet and passes the null payload without a check. A malicious or compromised RD Gateway can send an eight-byte CLOSE_CHANNEL header to crash a connecting FreeRDP client.

FreeRDP from 2.3.0 before 3.32.0 contains an infinite loop vulnerability in http_chuncked_read that allows malicious RD Gateways to hang clients by sending incomplete chunked responses. Attackers can send a partial chunk-size line or footer followed by a clean TLS shutdown, causing zero-byte reads to loop forever and freeze the client decoder thread.

FreeRDP 3.0.0-beta1 through 3.32.0 on Unix builds with PKCS#11 support has a stack-based buffer overflow in wprintKeyName() in WinPR's NCrypt PKCS#11 provider. It hex-encodes a key's CKA_ID, which can be up to 64 bytes, into a fixed 128-byte stack buffer. An attacker supplying a malicious PKCS#11 token or module whose key and matching certificate use a 55- to 64-byte CKA_ID can overflow the client's stack during key enumeration, causing a crash.

FreeRDP 3.0.0-beta4 through 3.32.0 contains a NULL pointer dereference in arm_handle_request_ok when an ARM endpoint returns an empty HTTP 200 body. Attackers controlling the configured ARM gateway can return a zero-length body to pass NULL to strnlen and crash the connecting client.