CVE-2019-6120
An issue was discovered in NiceHash Miner before 2.0.3.0. A missing rate limit while adding a wallet via Email address allows remote attackers to submit a large number of email addresses to identify valid ones. By exploiting this vulnerability with CVE-2019-6122 (Username Enumeration) an adversary can enumerate a large number of valid users’ Email addresses.
Source: CVE-2019-6120