High advisory for FreeRDP

Advisory overview

FreeRDP through 3.32.1 has a heap out-of-bounds write in the RDPGFX client because the delete_surface callback truncates surface hash keys to 16 bits, leaving the surface table inconsistent so HashTable_GetKeys writes past its allocated key array. A malicious or man-in-the-middle RDP server can exploit this by creating surfaceId 0xFFFF, closing the RDPGFX channel, sending repeated DELETESURFACE PDUs, and then sending ENDFRAME or RESETGRAPHICS.

Related references

• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m59q-wm7v-mp57
• https://www.vulncheck.com/advisories/freerdp-through-3.32.1-heap-out-of-bounds-write-via-rdpgfx-hashtable-getkeys
• https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m59q-wm7v-mp57