If a BIND resolver is performing DNSSEC validation and encounters a maliciously crafted zone, the resolver may consume excessive CPU. Authoritative-only servers are generally unaffected, although there are circumstances where authoritative servers may make recursive queries (see: https://kb.isc.org/docs/why-does-my-authoritative-server-make-recursive-queries). This issue affects BIND 9 versions 9.11.0 through 9.16.50, 9.18.0 through 9.18.46, 9.20.0 through 9.20.20, 9.21.0 through 9.21.19, 9.11.3-S1 through 9.16.50-S1, 9.18.11-S1 through 9.18.46-S1, and 9.20.9-S1 through 9.20.20-S1.
4.3.5-3ubuntu24.3.5-3ubuntu34.3.5-3ubuntu44.3.5-3ubuntu54.3.5-3ubuntu64.3.5-3ubuntu74.3.5-3ubuntu7.14.3.5-3ubuntu7.24.3.5-3ubuntu7.34.3.5-3ubuntu7.41:9.11.16+dfsg-3~build11:9.11.16+dfsg-3~ubuntu11:9.18.39-0ubuntu0.22.04.31:9.18.39-0ubuntu0.24.04.31:9.20.11-1ubuntu2.24.4.3-P1-4ubuntu21:9.9.5.dfsg-3ubuntu0.19+esm151:9.10.3.dfsg.P4-8ubuntu1.19+esm111:9.11.3+dfsg-1ubuntu1.19+esm61:9.18.30-0ubuntu0.20.04.2+esm3Exploitability
AV:NAC:LPR:NUI:NScope
S:UImpact
C:NI:NA:HCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H