Race condition in cpio 2.6 and earlier allows local users to modify permissions of arbitrary files via a hard link attack on a file while it is being decompressed, whose permissions are changed by cpio after the decompression is complete.

cpio on FreeBSD 2.1.0, Debian GNU/Linux 3.0, and possibly other operating systems, uses a 0 umask when creating files using the -O (archive) or -F options, which creates the files with mode 0666 and allows local users to read or overwrite those files