In Electric Coin Company Zcashd before 2.1.1-1, the time offset between messages could be leveraged to obtain sensitive information about the relationship between a suspected victim's address and an IP address, aka a timing side channel.

Electric Coin Company Zcashd before 2.1.1-1 allows attackers to trigger consensus failure and double spending. A valid chain could be incorrectly rejected because timestamp requirements on block headers were not properly enforced.