A service or binary that parses a custom archive format called .1zip .
If the goal is to read a flag located at /flag.txt , the exploit usually involves crafting a malicious .1zip file: Manually create a file with the 1ZIP header. Payload: Set the filename field to ../../../../flag.txt . 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 A service or binary that parses a custom
The first step in these challenges is usually reverse-engineering the .1zip header. Typically, the format includes: A sequence (e.g., 1ZIP ). Metadata for file count and individual file lengths. Filenames followed by the raw File Content . 2. Identifying the Vulnerability Upload or pass this file to the lhfs binary