The patch program applies diff files to originals. The diff command is used to compare an original to a changed file. Diff lists the changes made to the file. A person who has the original file can then use the patch command with the diff file to add the changes to their original file . Patch should be installed because it is a common way of upgrading applications. Security Fix: * patch: Malicious patch files cause ed to execute arbitrary commands For more details about the security issue, including the impact, a CVSS score, and other related information, refer to the CVE page listed in the References section.