Ethereum Contains Consensus Flaw During Block Processing

Impact

A vulnerability in the Geth EVM could cause a node to reject the canonical chain.

Description

A memory-corruption bug within the EVM can cause a consensus error, where vulnerable nodes obtain a different stateRoot when processing a maliciously crafted transaction. This, in turn, would lead to the chain being split in two forks.

All Geth versions supporting the London hard fork are vulnerable (which predates London), so all users should update.

This bug was exploited on Mainnet at block 13107518, leading to a minority chain split.

Patches

A patch is included in the v1.10.8 release. The exact patch to fix the issue is contained within this commit

Workarounds

No workarounds exist, save to update and/or apply the patch commit.

References.

Post-mortem write-up.

Credits

The bug was found by @guidovranken (working for Sentnl during an audit of the Telos EVM) and reported via [email protected].

For more information

If you have any questions or comments about this advisory:

• Open an issue in go-ethereum
• Email us at [email protected]