Zebra before 6.1.0 contains an incomplete cleanup vulnerability in the state write task that allows remote unauthenticated peers to stall node synchronization by poisoning parent_error_map. Attackers can deliver a coinbase-malleated block sharing a canonical blocks hash before it propagates, causing the next canonical block to be rejected and stalling the node for roughly 2,000 blocks.
Weakness
The product does not properly “clean up” and remove temporary or supporting resources after they have been used.