FreeRDP is a free implementation of the Remote Desktop Protocol. Prior to version 3.23.0, xf_cliprdr_provide_data_ passes freed pDstData to XChangeProperty because the cliprdr channel thread calls xf_cliprdr_server_format_data_response which converts and uses the clipboard data without holding any lock, while the X11 event thread concurrently calls xf_cliprdr_clear_cached_data → HashTable_Clear which frees the same data via xf_cached_data_free, triggering a heap use after free. Version 3.23.0 fixes the issue.
Exploitability
AV:NAC:LAT:NPR:NUI:NVulnerable System
VC:NVI:NVA:LSubsequent System
SC:NSI:NSA:N5.5/CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:PMemory Safety