Parity hack returns
In the previous chapter on solidity, we discussed the parity hack by the multi-signature wallet in the library contract. After that hack, the parity team had changed the library contract with the necessary fix. However, in doing so, they forgot to audit the other sections of the library smart contract, which had a new vulnerability.
Figure 8.10 shows the portion of the self-destruct code, which was available to outside users. A rookie developer with the alias name devops199 accessed this function and accidentally executed it. Hence, the entire library contract self-destructed and took itself off the blockchain.
The impact was realized much later when the wallets calling this library became meaningless and the tokens worth multimillion USD remained trapped forever in these dangling wallet contracts. Such hack stories make us realize the importance of peer review on any open source code and demonstrate why we should use hard wallets in place of a hot wallet.
Figure 8.10: Suicide...
