Fence Post

A secure vault application for authorized personnel. The developer wrote a custom input function — surely that's more secure than using standard library calls, right?

Binary Information:

Filename: fence-post
Size:     12,020 bytes (12 KB)
MD5:      ad55b85666fa6f773681bc77f49a0073
SHA1:     0b8a5bb0ab391e940509551f98abc269bb31f8a5
SHA256:   de1c630790ab6c7f59cd305b20d94ba3f70536e4853dcce290e5fb8335d05138

Verify integrity after download:

md5sum fence-post && sha1sum fence-post && sha256sum fence-post

Environment:
- Architecture: x86 (32-bit)
- Stack protector: Disabled
- NX: Enabled
- PIE: Disabled
- Symbols: Not stripped

Tip: Pay close attention to how the binary reads your input...

Note: Download the binary for local analysis. It reads flag.txt from the current directory — use a dummy flag for testing. The real flag can only be captured by exploiting the live instance on the lab.