CVE-2019-3979
RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below are vulnerable to a DNS unrelated data attack. The router adds all A records to its DNS cache even when the records are unrelated to the domain that was queried. Therefore, a remote attacker controlled DNS server can poison the router’s DNS cache via malicious responses with additional and untrue records.
Source: CVE-2019-3979