This week another vulnerability was discovered in the OpenSSL library. The vulnerability, given the idiotic marketing name Decrypting RSA with Obsolete and Weakened eNcryption (DROWN), allows an attacker to discover a server’s TLS session keys if it has SSLv2 enabled. Like FREAK and Logjam before it, DROWN was made possible by government meddling in cryptography:
For the third time in less than a year, security researchers have found a method to attack encrypted Web communications, a direct result of weaknesses that were mandated two decades ago by the U.S. government.
These new attacks show the dangers of deliberately weakening security protocols by introducing backdoors or other access mechanisms like those that law enforcement agencies and the intelligence community are calling for today.
Dubbed DROWN, this attack can be used to decrypt TLS connections between a user and a server if that server supports the old SSL version 2 protocol or shares its private key with another server that does. The attack is possible because of a fundamental weakness in the SSLv2 protocol that also relates to export-grade cryptography.
The U.S. government deliberately weakened three kinds of cryptographic primitives in the 1990s — RSA encryption, Diffie-Hellman key exchange, and symmetric ciphers — and all three have put the security of the Internet at risk decades later, the researchers who developed DROWN said on a website that explains the attack.
We’d all be safer if the government didn’t meddle in mathematical affairs.
This exploit also shows the dangers of supporting legacy protocols. While there may exist users that have software so old it doesn’t support TLS or even SSLv3, supporting them creates a hazard to every other user. There’s a point where you have to tell that user of ancient software to either upgrade to modern software or stop using the service. From a business standpoint, potentially losing one customer due to not having legacy support is far better than losing a lot of customers due to their trust in your company being lost because of a major security compromise.