Archive::Tar versions before 3.10 for Perl allow memory exhaustion via attacker controlled entry size field in tar header. _read_tar() reads each entry's payload with $handle->read($$data, $block), where $block is derived from the entry's 12-byte size field in the tar header with no upper bound on that value. A crafted header declaring a multi-gigabyte size causes Perl to allocate a scalar of that size.