FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to 3.20.1, a malicious RDP server can trigger a heap-buffer-overflow write in the FreeRDP client when processing Audio Input (AUDIN) format lists. audin_process_formats reuses callback->formats_count across multiple MSG_SNDIN_FORMATS PDUs and writes past the newly allocated formats array, causing memory corruption and a crash. This vulnerability is fixed in 3.20.1.