Privilege escalation via overflowing tar header fields

Improper input validation in Red Hat cpio before 2.13 allows local users to create tar archives that compromise a privileged extractor. The tar writer encodes file metadata into fixed-width octal header fields without rejecting values that exceed those fields, causing following content to parse as unintended archive entries. The attacker needs write access to an archived path, and a higher-privileged user must extract the archive without reviewing it, allowing files with unauthorized paths or permissions.