nimiq-blockchain vulnerabilities

In the nimiq-blockchain library (versions 1.3.0 and prior), network discovery accepts signed PeerContact updates from untrusted peers and stores them in the contact book, potentially causing an address book crash. An attacker can send a contact with an empty address list, causing a panic when accessing the address book.

nimiq-blockchain prior to version 1.4.0 has a vulnerability where a malicious network peer can crash any Nimiq full node by publishing a crafted Kademlia DHT record. The record contains a TaggedSigned<ValidatorRecord, KeyPair> with a signature field whose byte length is not exactly 64, causing a panic when unwrap() is called in the Ed25519 implementation. The BLS implementation correctly returns false, but Ed25519 panics.

In nimiq-blockchain before version 1.3.0, HistoryStore::put_historic_txns uses an assert! to enforce invariants about HistoricTransaction.block_number. During history sync, a peer can influence the input passed to Blockchain::push_history_sync, and a malformed history list can violate these invariants and trigger a panic before later rejection checks run.