BoringSSL through 2018-06-14 allows a memory-cache side-channel attack on DSA signatures, aka the Return Of the Hidden Number Problem or ROHNP. To discover a DSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host. https://www.nccgroup.trust/us/our-research/technical-advisory-return-of-the-hidden-number-problem/