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 Mem[DestPos].