First sites admit data loss through Heartbleed attacks

Canada’s tax authority and a popular British parenting website both lost user data after attackers exploited the Heartbleed SSL vulnerability, they said Monday.

The admissions are thought to be the first from websites that confirm data loss as a result of Heartbleed, which was first publicized last Tuesday. The flaw existed in Open SSL, a cryptographic library used by thousands of websites to enable encryption, and was quickly labeled one of the most serious security vulnerabilities in years.

The Canada Revenue Agency (CRA) blocked public access to its online services last Tuesday in reaction to the announcement, but that wasn’t fast enough to stop attackers from stealing information, it said on its website. “Regrettably, the CRA has been notified by the Government of Canada’s lead security agencies of a malicious breach of taxpayer data that occurred over a six-hour period. Based on our analysis to date, Social Insurance Numbers of approximately 900 taxpayers were removed from CRA systems by someone exploiting the Heartbleed vulnerability.”