The Link Library WordPress plugin before 7.9.6 does not sanitize a user-supplied destination folder before writing a generated image to disk, allowing users with the Contributor role and above to cre…

Summary

The Link Library WordPress plugin before 7.9.6 does not sanitize a user-supplied destination folder before writing a generated image to disk, allowing users with the Contributor role and above to create directories and write or overwrite image files anywhere the web server can write, including outside the site's document root. The written file name is always numeric with a fixed image extension, so executable code cannot be planted this way.