After checking thoroughly, we found that our servers themselves were not exposed as we currently use an old(er) version of Debian, yet, the loadbalancers we use have been vulnerable. Even though there is no trace (or proof) of that at this point, it is possible that user credentials and private data exchanged over a secure connection have been leaked, including passwords and tokens.
The vulnerability has been fixed and we have changed our SSL certificates as they could have been compromised. That means that it’s now safe (and strongly recommanded) for you to change your passwords and the tokens you use to authenticate against our API.
Please, note that it is also possible, but not confirmed, that an attacker stole your credit card information if you entered your credit card number on any site that asks for payment which was vulnerable (including Superfeedr). We also communicate with our provider using their API using SSL in a way which could have exposed this information. Because of this, we suggest you call your bank and ask them to issue a new card and invalidate the previous one.
Finally, as we know most of our customers run their own web applications, if you’re looking for a list of things to look for and fix in the wake of Heartbleed, we suggest you check Thomas’s post.
We also kindly ask that you report any suspicious activity under your account as soon as possible so we can take adequate measures for your accounts.