Amazon Linux 2 Security Advisory: ALASUNBOUND-1.17-2025-004
Advisory Release Date: 2025-03-13 01:32 Pacific
Advisory Updated Date: 2025-03-26 12:51 Pacific
Certain DNSSEC aspects of the DNS protocol (in RFC 4035 and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses when there is a zone with many DNSKEY and RRSIG records, aka the "KeyTrap" issue. The protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records. (CVE-2023-50387)
The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the "NSEC3" issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations. (CVE-2023-50868)
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 to update your system.
aarch64:
unbound-1.17.0-2.amzn2.0.6.aarch64
unbound-devel-1.17.0-2.amzn2.0.6.aarch64
unbound-libs-1.17.0-2.amzn2.0.6.aarch64
unbound-anchor-1.17.0-2.amzn2.0.6.aarch64
unbound-utils-1.17.0-2.amzn2.0.6.aarch64
python2-unbound-1.17.0-2.amzn2.0.6.aarch64
python3-unbound-1.17.0-2.amzn2.0.6.aarch64
unbound-debuginfo-1.17.0-2.amzn2.0.6.aarch64
src:
unbound-1.17.0-2.amzn2.0.6.src
x86_64:
unbound-1.17.0-2.amzn2.0.6.x86_64
unbound-devel-1.17.0-2.amzn2.0.6.x86_64
unbound-libs-1.17.0-2.amzn2.0.6.x86_64
unbound-anchor-1.17.0-2.amzn2.0.6.x86_64
unbound-utils-1.17.0-2.amzn2.0.6.x86_64
python2-unbound-1.17.0-2.amzn2.0.6.x86_64
python3-unbound-1.17.0-2.amzn2.0.6.x86_64
unbound-debuginfo-1.17.0-2.amzn2.0.6.x86_64