Bitcoin Unlimited Nodes Recover After Second Bug Exploit

A DoS attack exploiting a bug in the Bitcoin Unlimited client caused over 100 nodes to disconnect from the bitcoin network on Tuesday.

AccessTimeIconMar 23, 2017 at 12:15 p.m. UTC
Updated Sep 11, 2021 at 1:11 p.m. UTC
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Bitcoin Unlimited nodes that went offline following a denial-of-service attack on Tuesday are now functioning normally again, according to online data sources.

The issue, the second of its kind this month, was linked to a bug in the alternative bitcoin software that left an opening for the attack, causing over 100 BU nodes to disconnect from the network.

The erroneous code, related to the software's Xthin block architecture, was promptly fixed, and after the binary patch was released, the number of Bitcoin Unlimited nodes quickly recovered to pre-attack levels.

At press time, there are currently 806 nodes running Bitcoin Unlimited comprising 11.76% of the entire bitcoin network. This figure is up from a low of around 650 during the attack, according to data from Coin.Dance.

Yet, much of the debate on social media has since focused on questions relating to the capabilities of the Bitcoin Unlimited team, which is vying to release software that would effectively replace the standard issued by Bitcoin Core, the network's long-time development group.

On 13th March, a bug that allowed BU nodes to be remotely shut down was exploited, resulting in nearly 70% of nodes hosting the software to temporarily be sent offline.

Further, as part of the latest bug, developers opted to keep the changes private, initially only releasing the code's binary from a private repository. Tempers flared following this revelation, and were further stoked by the fact submitted improvements were not cryptographically signed by those who made them.

Additionally, the 'closed-source' code changes appear to have been leaked via Launchpad.

Coding image via Shutterstock


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