The Internet Systems Consortium (ISC) has released a security update that fixes a vulnerability in multiple versions of ISC Berkeley Internet Name Domain (BIND).
BIND (Berkely Internet Name Domain) is the most widely used Domain Name System software on the Internet.
The latest BIND patch addresses a vulnerability (CVE-2019-6477) that could result in a server memory leak and a denial of service (DoS).
As noted in the advisory, TCP-pipelined queries can bypass tcp-clients limit:
“With pipelining enabled each incoming query on a TCP connection requires a similar resource allocation to a query received via UDP or via TCP without pipelining enabled. A client using a TCP-pipelined connection to a server could consume more resources than the server has been provisioned to handle. When a TCP connection with a large number of pipelined queries is closed, the load on the server releasing these multiple resources can cause it to become unresponsive, even for queries that can be answered authoritatively or from cache. (This is most likely to be perceived as an intermittent server problem).”
System administrators should update to one of the following releases applicable to your organization’s current version:
- BIND 9.11.13
- BIND 9.14.8
- BIND 9.15.6
Finally, the BIND vulnerability is rated Moderate and CVSS base score of 6.5.