Libgcrypt before 1.7.10 and 1.8.x before 1.8.3 allows a memory-cache side-channel attack on ECDSA signatures that can be mitigated through the use of blinding during the signing process in the _gcry_ecc_ecdsa_sign function in cipher/ecc-ecdsa.c, aka the Return Of the Hidden Number Problem or ROHNP. To discover an ECDSA key, the attacker needs access to either the local machine or a different virtual machine on the same physical host.
Exploitability
AV:LAC:HPR:LUI:NScope
S:UImpact
C:HI:NA:N4.7/CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N