CA compromise

Work in Progress

Summary

Premise

CA infrastructure has inadequate security (weak PKI hygiene, poor isolation, unpatched systems).
Attacker obtains access to CA signing keys or CA internal system.
The CA is trusted by browsers/OS.

Attack

Extracts the CA’s private signing key or forces CA server to sign certificates.
Issues valid certificates for arbitrary domains (e.g., google.com).

Uses them in MITM attacks (e.g., via DNS poisoning, BGP hijacking, or Wi-Fi MITM).

Attacker’s Goals

Impersonate any HTTPS site trusted by that CA.
Intercept and decrypt secure communications.
Launch large-scale MITM attacks invisibly.

Defense

Hardware Security Modules (HSM) for private key storage.
Strong internal access control and monitoring.
Certificate Transparency (CT) logs — public audit of all certificates.
Browser/OS vendors “distrust” CAs that misbehave (Chrome Root Program).
Key ceremony & strict physical/process security.

Concept