Medium [CVE-2026-67289] HTTP Proxy Request Injection via Redirection

FreeRDP before 3.29.0 (affected versions <= 3.28.0) does not validate CRLF and control characters in the server-controlled RDP redirection TargetNetAddress field.

This value is copied into the client's ServerHostname and, when the client connects through an HTTP proxy, is written directly into the proxy CONNECT request line and Host header by http_proxy_connect() without filtering.

A malicious or compromised RDP server can send a crafted redirection PDU containing embedded control characters to inject arbitrary headers/requests into the HTTP proxy CONNECT request. A flaw was found in FreeRDP.

This injection could allow an attacker to manipulate the proxy's behavior or bypass certain network security policies. Moderate: This client-side vulnerability in FreeRDP allows for HTTP proxy request injection.

Exploitation requires a FreeRDP client to be configured to use an HTTP proxy and to connect to a malicious or compromised RDP server, which then sends a crafted redirection PDU. This limits the attack surface to specific client configurations and interactions with untrusted RDP endpoints.

Red Hat severity: Moderate — CVSS 5 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L). Weakness: CWE-93.