FreeRDP before 3.0.0 and 3.6.0 before 3.32.0 renders uninitialized heap memory from un-decoded progressive tiles because the tile->current buffer is allocated without zeroing. A malicious RDP server can send a crafted WBT_TILE_FIRST then WBT_TILE_UPGRADE sequence to paint heap bytes onscreen or abort the client process.

FreeRDP before 3.0.0 and 3.6.0 before 3.32.0 renders uninitialized heap memory from un-decoded progressive tiles because the tile->current buffer is allocated without zeroing. A malicious RDP server can send a crafted WBT_TILE_FIRST then WBT_TILE_UPGRADE sequence to paint heap bytes onscreen or abort the client process.