Just to provide more insight into the matter, we use the Amazon Elastic Load Balancer for a SSL passthrough so the nginx component is not affected.
1) Amazon fixed the exploit pretty early during the Heartbleed chaos so we were safe there.
2) Additionally, we updated our SSL certs in March which also kept us safe as well.
On Thursday, we'll be moving to a new datacenter and netscalers which will provide an additional level of protection.
As a very security conscious user (I listen to the Security Now podcast and do follow various 'net-sec' experts)
Amazon has recommend users of SSL termination via Amazon Elastic Load Balancer reissue the certificates for their sites.
Pretty much any SSL certificate that was generated before April 7-8th is potentially compromised due to this bug this INCLUDES if the same certificate is used AFTER PATCHING AFFECTED SYSTEMS.
I understand that revoking and renewing SSL keys is a pain in the ass (especially combined with the rush of a lot of other users/services/companies doing the same) but this is as security expert Brian Schneier described it "(In terms of describing the scale of damage possible with this exploit) On the scale of 1 to 10, this is an 11".
But consider the following if you have not researched the overall impact and scope of this bug:
If you don't revoke your certificate, you may still be vulnerable to impersonation
If a remote attacker successfully retrieved private keys from a server while it was still vulnerable to the Heartbleed bug, then he would be able to impersonate the server by creating his own valid SSL certificate. The crucial issue is that an attacker can still do this after the affected website has upgraded to the latest version of OpenSSL, and it does not matter whether the real website has since deployed a new SSL certificate with different keys: Unless the previous certificate is revoked, the site will still be vulnerable to man-in-the-middle attacks.
This answer on securityexchange.com also points out the implication of having vulnerable servers:
There is more to consider than just new certificates (or rather, new key pairs) for every affected server. It also means:
- Patching affected systems to OpenSSL 1.0.1g
- Revocation of the old keypairs that were just supersceded
- Changing all passwords
- Invalidating all session keys and cookies
- Evaluating the actual content handled by the vulnerable servers that could have been leaked, and reacting accordingly.
- Evaluating any other information that could have been revealed, like memory addresses and security measures
Also from the same answer:
I summarized the bullet points above from heartbleed.com (emphasis mine):
What is leaked primary key material and how to recover?
These are the crown jewels,. Leaked secret keys allows the attacker to decrypt any past and future traffic to the protected services and to impersonate the service at will. Any protection given by the encryption and the signatures in the X.509 certificates can be bypassed. Recovery from this leak requires patching the vulnerability, revocation of the compromised keys and reissuing and redistributing new keys. Even doing all this will still leave any traffic intercepted by the attacker in the past still vulnerable to decryption. All this has to be done by the owners of the services.
What is leaked secondary key material and how to recover?
These are for example the used in the vulnerable services. Recovery from this leaks requires owners of the service first to restore trust to the service according to steps described above. After this users can start changing their passwords and possible encryption keys according to the instructions from the owners of the services that have been compromised. All session keys and session cookies should be invalided and considered compromised.
What is leaked protected content and how to recover?
This is . It may be personal or financial details, private communication such as emails or instant messages, documents or anything seen worth protecting by encryption. Only owners of the services will be able to estimate the likelihood what has been leaked and they should notify their users accordingly. Most important thing is to restore trust to the primary and secondary key material as described above. Only this enables safe use of the compromised services in the future.
What is leaked collateral and how to recover?
Leaked collateral are to the attacker in the leaked memory content. These may contain technical details such as memory addresses and security measures such as canaries used to protect against overflow attacks. These have only contemporary value and will lose their value to the attacker when OpenSSL has been upgraded to a fixed version.