CVE-2025-11411

Publication date 22 October 2025

Last updated 3 December 2025

Ubuntu priority

Medium

Why this priority?

Description

NLnet Labs Unbound up to and including version 1.24.2 is vulnerable to possible domain hijack attacks. Promiscuous NS RRSets that complement positive DNS replies in the authority section can be used to trick resolvers to update their delegation information for the zone. Usually these RRSets are used to update the resolver's knowledge of the zone's name servers. A malicious actor can exploit the possible poisonous effect by injecting NS RRSets (and possibly their respective address records) in a reply. This could be done for example by trying to spoof a packet or fragmentation attacks. Unbound would then proceed to update the NS RRSet data it already has since the new data has enough trust for it, i.e., in-zone data for the delegation point. Unbound 1.24.1 includes a fix that scrubs unsolicited NS RRSets (and their respective address records) from replies mitigating the possible poison effect. Unbound 1.24.2 includes an additional fix that scrubs unsolicited NS RRSets (and their respective address records) from YXDOMAIN and non-referral nodata replies, further mitigating the possible poison effect.

Read the notes from the security team

Status

Package Ubuntu Release Status
unbound 25.10 questing
Fixed 1.22.0-2ubuntu2.2
25.04 plucky
Fixed 1.22.0-1ubuntu1.3
24.04 LTS noble
Fixed 1.19.2-1ubuntu3.7
22.04 LTS jammy
Fixed 1.13.1-1ubuntu5.14
20.04 LTS focal
Needs evaluation
18.04 LTS bionic
Needs evaluation
16.04 LTS xenial
Needs evaluation
14.04 LTS trusty
Needs evaluation

Notes

hlibk

Upstream has noted that the original fix was incomplete, and as part of version 1.24.2 released another patch to fully address the issue.

Patch details

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

Package Patch details
unbound

References

Related Ubuntu Security Notices (USN)

Other references