FreeRDP before 3.29.0 contains a buffer over-disclosure vulnerability in the gateway WebSocket transport (libfreerdp/core/gateway/websocket.c). The client's Pong reply reuses a fixed 1024-byte response stream whose length is not sealed to the actual received Ping payload, so a malicious gateway/WebSocket peer sending a non-empty Ping control frame causes the client to reply with an overlong Pong that discloses bytes beyond the received payload (the peer receives the masking key and can unmask the reply). A zero-length Ping reaches an assertion and terminates the client (denial of service).
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 3
https://github.com/FreeRDP/FreeRDP/commit/f3b4347105114fe7453828736bea069999af3…
disclosure@vulncheck.com
https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-8v6m-2cmc-chx9
disclosure@vulncheck.com
https://www.vulncheck.com/advisories/freerdp-before-websocket-ping-buffer-over-…
disclosure@vulncheck.com