Knot Resolver before 5.1.1 allows traffic amplification via a crafted DNS answer from an attacker-controlled server, aka an "NXNSAttack" issue. This is triggered by random subdomains in the NSDNAME in NS records.
{ "binaries": [ { "binary_version": "2.1.1-1ubuntu0.1~esm2", "binary_name": "knot-resolver" }, { "binary_version": "2.1.1-1ubuntu0.1~esm2", "binary_name": "knot-resolver-module-http" }, { "binary_version": "2.1.1-1ubuntu0.1~esm2", "binary_name": "libkres-dev" }, { "binary_version": "2.1.1-1ubuntu0.1~esm2", "binary_name": "libkres6" } ] }