Automated scanners are great at testing a running application from the outside. But some of the most damaging bugs are invisible from there — they only show up when a human reads the source.

TL;DR

Reading an SDK or codebase surfaces flaws a black-box scanner cannot see: secrets written to logs, a validator that approves everything, CSRF protection left disabled, fail-open authentication. If you ship or depend on SDKs, get the code reviewed — not just the endpoints scanned.

What scanners cannot see

A scanner sends requests and judges responses. It cannot tell that, three files deep, a master key is printed to a log, that a "validate" function returns true unconditionally, or that an OAuth flow set its anti-CSRF state to undefined. Those are reading-the-code findings.

Classes we routinely find by reading code

• Secrets in logs — keys, tokens, and seeds printed at startup or on error, then captured by your log pipeline forever.
• Disabled safety checks — "approve everything" test validators, or flags that quietly turn off validation in production.
• Missing CSRF state — OAuth flows with no state parameter, opening the door to account takeover.
• Fail-open auth — code that, when a token check fails, proceeds without authentication instead of stopping.

Why it matters

These bugs are often Critical (full account or fund compromise) yet completely invisible to scanning. Combining automated coverage with human source review is how you catch both.

Our penetration testing pairs automated testing with manual code review, and Faseel Suite gives you the automated half on every release.