Use-after-free vulnerability in bitlbee-libpurple before 3.5 allows remote servers to cause a denial of service (crash) or possibly execute arbitrary code by causing a file transfer connection to expire.

BitlBee before 3.5 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) and possibly execute arbitrary code via a file transfer request for a contact that is not in the contact list.