According to the Litecoin Foundation, Litecoin underwent a major reorganization of its chain on Saturday after attackers exploited a zero-day bug related to its MimbleWimble Extension Block privacy layer.
Summary
- Litecoin reversed 13 blocks after attackers exploited a zero-day bug in its MWEB privacy layer.
- Attackers used the fork window to attempt to double spend against multiple cross-chain swap protocols.
- The Litecoin Foundation said the bug had been fixed, while some sites reported losses.
The Foundation said the bug allowed old mining nodes to accept an invalid MWEB transaction. This created a fork that lasted for over three hours before the network restored the main channel.
Invalid transactions cleared from chain history
The incident affected blocks 3,095,930 to 3,095,943, according to Alex Shevchenko, CEO of Aurora Labs. He described the event as a “coordinated attack” in an article on X.
A 13-block reorganization removed invalid transactions from Litecoin’s main history. The Foundation said valid transactions made during this period were not affected.
Additionally, attackers used the fork window to attempt double-spending transactions against cross-chain swap protocols. These platforms had accepted MWEB anchors which became invalid after the reorganization.
Shevchenko said: “The exposure of NEAR Intents is approximately $600,000. » He also warned trading platforms to review Litecoin transactions and balances, adding: “We are seeing a lot of double-spending transactions.”
The Foundation says the bug is fixed
The Litecoin Foundation said that the zero-day bug has now been fully fixed. It did not name the affected mining pools or disclose the amount of LTC the invalid transactions attempted to create.
This is the first known major exploit targeting MWEB since Litecoin enabled the privacy feature in May 2022. LTC traded near $56 after the disclosure, down about 1% on the day.
