The remote DNS server is vulnerable to a denial of service attack.
The remote host is running Bind, a popular name server. Versions of BIND 9.4-ESV earlier than 9.4-ESV-R5-P1, 9.6-ESV earlier than 9.6-ESV-R5-P1, 9.7.x earlier than 9.7.4-P1, and 9.8.x earlier than 9.8.1-P1 are potentially affected by a denial of service vulnerability. An unidentified network event causes BIND9 resolvers to cache an invalid record, subsequent queries for which could crash the resolvers with an assertion failure.
Upgrade to BIND 9.4-ESV-R5-P1 / 9.6-ESV-R5-P1, 9.7.4-P1, 9.8.1-P1, or later.