Php

A PHP upload app re-encodes every GIF through PHP-GD as sanitization but never validates the filename — a payload smuggled inside the GIF color palette survives the re-encode, yielding a GIF/PHP polyglot webshell and RCE.

A 4-digit PIN with no rate limiting falls to brute force, the dashboard’s ORDER BY sort is blind-SQL-injectable, and the home-made sanitizer only strips ‘<’ — so boolean extraction with ‘>’ dumps the secrets table.

An MD5-only oracle over arbitrary paths is turned into a full file disclosure using the error-based PHP filter-chain oracle to leak /flag byte-by-byte.