Isc · Bind · CVE-2020-8620
**Name of the Vulnerable Software and Affected Versions**
BIND versions 9.15.6 through 9.16.5
BIND versions 9.17.0 through 9.17.3
**Description**
The issue is related to the libuv library in the BIND DNS server, which can be exploited by an attacker who can establish a TCP connection with the server and send data on that connection, causing the server to exit due to an assertion failure. This can be triggered by sending a specific set of packets to the TCP port on which the BIND server accepts connections, including large AXFR requests that can cause the libuv library to pass a size to the server that triggers the assertion check and process termination.
**Recommendations**
For BIND versions 9.15.6 through 9.16.5, update to version 9.16.6 or later.
For BIND versions 9.17.0 through 9.17.3, update to version 9.17.4 or later.
As a temporary workaround, consider restricting access to the TCP port on which the BIND server accepts connections to minimize the risk of exploitation.