CVE-2023-50387

Publication date 13 February 2024

Last updated 21 October 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.

Read the notes from the security team

Status

Package Ubuntu Release Status
bind9 26.10 stonking
Fixed in 1:9.18.24-0ubuntu1
26.04 LTS resolute
Fixed in 1:9.18.24-0ubuntu1
25.10 questing
Fixed in 1:9.18.24-0ubuntu1
25.04 plucky
Fixed in 1:9.18.24-0ubuntu1
24.10 oracular
Fixed in 1:9.18.24-0ubuntu1
24.04 LTS noble
Fixed in 1:9.18.24-0ubuntu1
23.10 mantic
Fixed in 1:9.18.18-0ubuntu2.1
22.04 LTS jammy
Fixed in 1:9.18.18-0ubuntu0.22.04.2
20.04 LTS focal
Fixed in 1:9.16.48-0ubuntu0.20.04.1
18.04 LTS bionic
Fixed in 1:9.11.3+dfsg-1ubuntu1.19+esm3
16.04 LTS xenial
Fixed in 1:9.10.3.dfsg.P4-8ubuntu1.19+esm8
14.04 LTS trusty
Fixed in 1:9.9.5.dfsg-3ubuntu0.19+esm12
isc-dhcp 26.10 stonking Not in release
26.04 LTS resolute
Needs evaluation
25.10 questing Ignored end of life, was needs-triage
25.04 plucky Ignored end of life, was needs-triage
24.10 oracular Ignored end of life, was needs-triage
24.04 LTS noble
Needs evaluation
23.10 mantic Ignored end of life, was needs-triage
22.04 LTS jammy
Not affected
20.04 LTS focal
Not affected
18.04 LTS bionic
Not affected
16.04 LTS xenial
Not affected
14.04 LTS trusty
Not affected
bind9-libs 26.10 stonking Not in release
26.04 LTS resolute Not in release
25.10 questing Not in release
25.04 plucky Not in release
24.10 oracular Not in release
24.04 LTS noble Not in release
23.10 mantic Not in release
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic Not in release
16.04 LTS xenial Not in release
14.04 LTS trusty Not in release
unbound 26.10 stonking
Fixed in 1.19.1-1ubuntu1
26.04 LTS resolute
Fixed in 1.19.1-1ubuntu1
25.10 questing
Fixed in 1.19.1-1ubuntu1
25.04 plucky
Fixed in 1.19.1-1ubuntu1
24.10 oracular
Fixed in 1.19.1-1ubuntu1
24.04 LTS noble
Fixed in 1.19.1-1ubuntu1
23.10 mantic
Fixed in 1.17.1-2ubuntu0.1
22.04 LTS jammy
Fixed in 1.13.1-1ubuntu5.4
20.04 LTS focal
Fixed in 1.9.4-2ubuntu1.5
18.04 LTS bionic
Fixed in 1.6.7-1ubuntu2.6+esm6
16.04 LTS xenial
Fixed in 1.5.8-1ubuntu1.1+esm5
14.04 LTS trusty
Fixed in 1.4.22-1ubuntu4.14.04.3+esm5
dnsmasq 26.10 stonking
Fixed in 2.90-1
26.04 LTS resolute
Fixed in 2.90-1
25.10 questing
Fixed in 2.90-1
25.04 plucky
Fixed in 2.90-1
24.10 oracular
Fixed in 2.90-1
24.04 LTS noble
Fixed in 2.90-1
23.10 mantic
Fixed in 2.90-0ubuntu0.23.10.1
22.04 LTS jammy
Fixed in 2.90-0ubuntu0.22.04.1
20.04 LTS focal
Fixed in 2.90-0ubuntu0.20.04.1
18.04 LTS bionic
Fixed in 2.90-0ubuntu0.18.04.1+esm1
16.04 LTS xenial
Fixed in 2.90-0ubuntu0.16.04.1+esm1
14.04 LTS trusty
Not affected
pdns-recursor 26.10 stonking
Not affected
26.04 LTS resolute
Not affected
25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic Ignored end of life, was needs-triage
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Ignored end of standard support
knot-resolver 26.10 stonking
Not affected
26.04 LTS resolute
Not affected
25.10 questing
Not affected
25.04 plucky
Not affected
24.10 oracular
Not affected
24.04 LTS noble
Not affected
23.10 mantic Ignored end of life, was needs-triage
22.04 LTS jammy
Needs evaluation
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty Not in release

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Notes

alexmurray

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs

mdeslaur

This is unlikely to affect isc-dhcp's use of bind9-libs and the vendored bind9 libs, marking as negligible

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
bind9
unbound

Severity score breakdown

CVSS version: CVSS v3.0

Base score 7.5 · High

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

Other references

Access our resources on patching vulnerabilities