Secure Code Review: Finding Injection Bugs

The methodology gave you sources, sinks and taint; now we put it to work on real source, spotting the injection family by eye. For SQL injection, command injection (RCE), XSS, path traversal, SSRF and template/XML injection we show the vulnerable pattern, the grep that finds it, and the fix — across PHP, Python, Node and Java. You learn the one shape every injection shares, plus the false-positive traps that catch beginners.