A VMSF_DELTA memory corruption was discovered in unrar before 5.5.5 as used in Sophos Anti-Virus Threat Detection Engine before 3.37.2 and other products that can lead to arbitrary code execution. An integer overflow can be caused in DataSize+CurChannel. The result is a negative value of the \DestPos\ variable which allows the attacker to write out of bounds when setting MemDestPos.