4 ms·
1. User validates domain and submits csr 2. Rootkit swaps out csr with one of its own whose private key is under its control and submits upstream to the CA 3. C
by 0x0 9y ago
1. User validates domain and submits csr
2. Rootkit swaps out csr with one of its own whose private key is under its control and submits upstream to the CA
3. CA signs a cert because the domain was validated
4. Rootkit receives valid cert for its own private key
5. Rootkit presents a bogus error to enduser
6. Enduser tries again and rootkit lets it through
End-result: there are now two certs and private keys for the domain, one of which is compromised?
Just a though experiment. I'm not familiar with the domain validation flow this reseller site was using.
- Xylakant 9y agoLike I said: If you compromise the Trustico servers which are a reseller, you could trick the CA into believing that a CSR is valid for a domain. This would get you a certificate with a key under your control. But revoking the certificate with the key under the owners control won’t fix this. The illegitimate certificate would still be under the attackers control and remain valid.
- 0x0 9y agoUnless you revoke all the certs issued through that channel/reseller - the legitimates would be collateral damage but you'd also get rid of any illegitimate ones?
- pixl97 9y agoCertificate transparency logs would out that pretty quickly.
- zaarn 9y ago1. Rootkit issues cert and sends to hacker I find this plan to be much much easier.
- 0x0 9y agoPresumably, even if you had root on the reseller website, you would need to wait for the domain owner to actually perform a domain validation before the actual CA's system would deliver any certificates?
- zaarn 9y agoConsidering the security on that website, probably not. Even if you did, I would argue that if you have root access to the validation form, getting a certificate signed is not going to be exponentially harder either. Waiting for a potential target to sign a cert using that specific reseller is just borderline useless. An attacker of a CA will be interested in either their CA private key (or intermediary) or the ability to get arbitrary certs signed. Random targets on the internet are useless since it's unlikely they can MitM them.