While Bitcoin (BTC) is the first, largest, and the most popular cryptocurrency, it is certainly not perfect. Even though the it is often seen as a standard for the crypto world, a single flaw in the right place would be enough to bring it down.
One such flaw was detected quite recently, and this Tuesday, Bitcoin Core developers successfully released a new software version that patched the vulnerability. Despite the fact that the developers reacted quickly, and the flaw was handled in no time, its exploit could have led to a disaster if it made it to production release. In fact, a malicious user could have easily crashed the entire network if they found it before the developers.
But, bugs never make it to production release, as they are often discovered and patched in the review process.
Bitcoin Core 0.16.3 was released: https://t.co/SsbsJsqSTo
Upgrade recommended due to vulnerability fix
— Bitcoin Core Project (@bitcoincoreorg) September 18, 2018
If the network were to fall, the network could have been temporarily unusable. Obviously, this is a very serious problem, and it is considered to be one of the top 3 flaws ever found on Bitcoin according to reports.
According to Cornell University computer science’s professor, Emin Gün Sirer, the network could have been brought down for less than $80,000. He claims that even 0-day attacks often cost more than that and that the motivated individual could have destroyed Bitcoin forever.
It should be pointed out that the bug was not found in the protocol itself. Instead, it was discovered in its software implementation. This means that other cryptos created through the use of Bitcoin Core code are vulnerable as well, like Litecoin, for example. Still, holders of Litecoin do not have to worry, this bug was patched as well.
The potential consequences of the exploit
The official reports describe the bug as a denial-of-service vulnerability. Reportedly, it was present in Bitcoin Core since last year, and it allowed miners to make “poisoned” blocks by including fake transactions that are spending the same coins more than once. The poisoned block would then crash the software of pretty much everyone who receives it.
This is usually impossible since BTC is a P2P network that can work due to numerous nodes that are used to confirm that each transaction corresponds to the rules of the blockchain. However, since around 95% of the nodes are using Core, all of them could have been instantly killed by the poisoned block. And that’s not the worst part — it also had a potential to completely crash the entire network.
Despite the danger, the disaster was avoided, which is all that matters in the end. Besides, as Andreas M. Antonopoulos said, Core’s track record is still the best in the industry, which is why investors should not be discouraged from using the coin.
a) Never say never.
b) The Bitcoin Core project's track record of quality remains the best in the industry, by far. https://t.co/FAy5n8KxJf
— Andreas M. Antonopoulos (@aantonop) September 19, 2018