Amazon Linux 2 Security Advisory: ALAS2UNBOUND-1.17-2025-006
Advisory Released Date: 2025-11-05
Advisory Updated Date: 2025-11-05
NLnet Labs Unbound up to and including version 1.24.0 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. (CVE-2025-11411)
Affected Packages:
unbound
Note:
This advisory is applicable to Amazon Linux 2 - Unbound-1.17 Extra. Visit this page to learn more about Amazon Linux 2 (AL2) Extras and this FAQ section for the difference between AL2 Core and AL2 Extras advisories.
Issue Correction:
Run yum update unbound or yum update --advisory ALAS2UNBOUND-1.17-2025-006 to update your system.
aarch64:
unbound-1.17.0-2.amzn2.0.8.aarch64
unbound-devel-1.17.0-2.amzn2.0.8.aarch64
unbound-libs-1.17.0-2.amzn2.0.8.aarch64
unbound-anchor-1.17.0-2.amzn2.0.8.aarch64
unbound-utils-1.17.0-2.amzn2.0.8.aarch64
python2-unbound-1.17.0-2.amzn2.0.8.aarch64
python3-unbound-1.17.0-2.amzn2.0.8.aarch64
unbound-debuginfo-1.17.0-2.amzn2.0.8.aarch64
src:
unbound-1.17.0-2.amzn2.0.8.src
x86_64:
unbound-1.17.0-2.amzn2.0.8.x86_64
unbound-devel-1.17.0-2.amzn2.0.8.x86_64
unbound-libs-1.17.0-2.amzn2.0.8.x86_64
unbound-anchor-1.17.0-2.amzn2.0.8.x86_64
unbound-utils-1.17.0-2.amzn2.0.8.x86_64
python2-unbound-1.17.0-2.amzn2.0.8.x86_64
python3-unbound-1.17.0-2.amzn2.0.8.x86_64
unbound-debuginfo-1.17.0-2.amzn2.0.8.x86_64