Share this article

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.

Updated Sep 11, 2021, 1:11 p.m. Published Mar 23, 2017, 12:15 p.m.
software code

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.

STORY CONTINUES BELOW
Don't miss another story.Subscribe to the Crypto Daybook Americas Newsletter today. See all newsletters

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

More For You

Protocol Research: GoPlus Security

GP Basic Image

What to know:

  • As of October 2025, GoPlus has generated $4.7M in total revenue across its product lines. The GoPlus App is the primary revenue driver, contributing $2.5M (approx. 53%), followed by the SafeToken Protocol at $1.7M.
  • GoPlus Intelligence's Token Security API averaged 717 million monthly calls year-to-date in 2025 , with a peak of nearly 1 billion calls in February 2025. Total blockchain-level requests, including transaction simulations, averaged an additional 350 million per month.
  • Since its January 2025 launch , the $GPS token has registered over $5B in total spot volume and $10B in derivatives volume in 2025. Monthly spot volume peaked in March 2025 at over $1.1B , while derivatives volume peaked the same month at over $4B.

More For You

Bitcoin’s Deep Correction Sets Stage for December Rebound, Says K33 Research

(Unsplash)

K33 Research says market fear is outweighing fundamentals as bitcoin nears key levels. December could offer an entry point for bold investors.

What to know:

  • K33 Research says bitcoin’s steep correction shows signs of bottoming, with December potentially marking a turning point.
  • The firm has argued that the market is overreacting to long-term risks while ignoring near-term signals of strength, like low leverage and solid support levels.
  • With likely policy shifts ahead and cautious positioning in futures, K33 sees more upside potential than risk of another major collapse.