OpenShift oc: malicious image layers can write files outside extraction directory

A flaw was found in the OpenShift client oc. When extracting container image layers with oc image extract, the application fails to properly sanitize symbolic and hard link targets pointing to absolute paths or to sibling directories of the extraction destination. An attacker who supplies a malicious container image can exploit this vulnerability by embedding links, and a chained file entry, that reference locations outside the intended extraction directory. This allows the attacker to write attacker-controlled content to arbitrary locations on the host filesystem with the privileges of the user running the command, potentially leading to file modification outside the destination directory.