Every breach has a chain of events. Misconfigured TLS is often the first link in that chain. Strong encryption is not enough if your TLS configuration opens the door through outdated protocols, broken ciphers, or lazy certificate policies. Attackers scan for these mistakes every day, and they move fast when they find them.
A proper TLS setup starts with removing legacy protocols like TLS 1.0 and 1.1. They are broken and exploitable. Force all connections to TLS 1.2 or higher, and prefer TLS 1.3 wherever possible. Strip out weak ciphers. Avoid static key exchanges. Disable null ciphers, RC4, 3DES. Use AES-GCM or ChaCha20-Poly1305. Set forward secrecy as a non-negotiable.
Certificates deserve equal discipline. Never let them expire without tracking. Use 2048-bit or stronger keys. Check for proper certificate chains and intermediate certificates. Turn off wildcard abuse when possible. Monitor OCSP responses to ensure revocation status is accurate in real time.
Don’t ignore handshake policies. Define strict ALPN and SNI handling. Ensure your session resumption strategy doesn’t leak state. In high-security contexts, disable session tickets or rotate their keys aggressively.