K02663161 : BIND vulnerability CVE-2020-8622

Security Advisory Description

In BIND 9.0.0 -> 9.11.21, 9.12.0 -> 9.16.5, 9.17.0 -> 9.17.3, also affects 9.9.3-S1 -> 9.11.21-S1 of the BIND 9 Supported Preview Edition, An attacker on the network path for a TSIG-signed request, or operating the server receiving the TSIG-signed request, could send a truncated response to that request, triggering an assertion failure, causing the server to exit. Alternately, an off-path attacker would have to correctly guess when a TSIG-signed request was sent, along with other characteristics of the packet and message, and spoof a truncated response to trigger an assertion failure, causing the server to exit. (CVE-2020-8622)

Impact

This vulnerability affects systems that use the BIND process. When an attacker sends or spoofs a truncated response to a TSIG-signed request received by the BIND process, the BIND process experiences an assertion failure and exits while attempting to verify the truncated response. As a result, the system experiences a denial-of-service (DoS) attack on the BIND process.