Lhfs_1zip

If the extraction tool doesn't sanitize filenames, you can use ../ to write files outside the intended directory (e.g., overwriting .ssh/authorized_keys or /etc/passwd ).

A service or binary that parses a custom archive format called .1zip . lhfs_1zip

Upload or pass this file to the lhfs binary. If vulnerable, it will attempt to "extract" the file to that path or read from it, often leaking the contents in the process. Common Mitigation If the extraction tool doesn't sanitize filenames, you

Creating a symlink inside the archive that points to a sensitive system file. When the service "updates" or "reads" the file, it interacts with the system target instead. 3. Exploitation (General Example) If vulnerable, it will attempt to "extract" the

If you are writing the "defense" side of this write-up, the fix is to the extraction process or strictly sanitize filenames to remove any .. or leading / characters. g., PicoCTF, SECCON, or HTB) where this challenge appeared?

While a specific "official" write-up might be hosted on private CTF platforms (like Hack The Box or specific university labs), the challenge typically revolves around exploiting a implementation that handles .1zip files. Challenge Overview