Insufficient sanitizing in the TeX notation filter resulted in an arbitrary file read risk on sites where pdfTeX is available (such as those with TeX Live installed).
The product makes files or directories accessible to unauthorized actors, even though they should not be.
Web servers, FTP servers, and similar servers may store a set of files underneath a “root” directory that is accessible to the server’s users. Applications may store sensitive files underneath this root without also using access control to limit which users may request those files, if any. Alternately, an application might package multiple files or directories into an archive file (e.g., ZIP or tar), but the application might not exclude sensitive files that are underneath those directories. In cloud technologies and containers, this weakness might present itself in the form of misconfigured storage accounts that can be read or written by a public or anonymous user.