InfraGuard

Detection rule: STARTTLS Downgrade

No TLS switch after STARTTLS negotiation.

CriticalProtocol AnomalySuricata

What it detects

No TLS switch after STARTTLS negotiation.

Why it fires

Signals a forced downgrade to intercept cleartext.

Worst case

Cleartext eavesdrop · downgrade

Matching signatures

no tls after starttls

Track these versions on your own servers

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