Your pipeline stalled. Your scan lit up with red. The TLS layer was the weak link.
IAST TLS configuration is not optional. Interactive Application Security Testing only works when your application’s communication is secure and correctly instrumented. If TLS is misconfigured, your IAST sensors will miss traffic, misread encrypted payloads, and fail to detect critical vulnerabilities.
Start with the basics. Use strong ciphers only. Drop support for outdated protocols like TLS 1.0 and 1.1. Enforce TLS 1.2 or TLS 1.3 for all application endpoints. Configure your server and client libraries to reject weak cipher suites. Check certificate chains — expired or self-signed certs will break instrumentation and trigger false negatives.
Instrument with precision. Place IAST agents where they can inspect decrypted data before and after encryption. In Java, hook into the SSL/TLS handshake functions via supported instrumentation APIs. In .NET and Node.js, verify that libraries expose raw data for the agent before transport encryption starts. If your TLS configuration terminates at a reverse proxy, ensure the IAST agent runs at that proxy or deeper inside the app.