FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.28.0, freerdpdspdecodeopus in libfreerdp/codec/dsp.c calls StreamEnsureRemainingCapacity on context->common.buffer even though opusdecode writes decoded PCM into the caller-supplied out stream. A malicious RDP server that negotiates WAVEFORMATOPUS with a client built with WITHOPUS enabled and WITHDSPFFMPEG disabled can make libopus write a large decoded frame beyond the 4096-byte StreamPoolTake destination used by channels/rdpsnd/client/rdpsndmain.c. This can corrupt the client heap, crash the client, and may permit code execution. This issue is fixed in version 3.28.0.

FreeRDP before 3.29.0 (affected versions <= 3.28.0) contains an improper certificate hostname validation vulnerability. The TLS hostname matcher (tlsmatchhostname() in libfreerdp/crypto/tls.c) treats a wildcard pattern such as .example.com as matching any hostname ending in .example.com, so it incorrectly accepts a wildcard certificate for multi-label subdomains like a.b.example.com (which OpenSSL's X509checkhost() rejects). This weakens TLS server authentication under wildcard-certificate conditions.