Amazon Linux 2 Security Advisory: ALASDNSMASQ-2024-002
Advisory Release Date: 2024-04-10 22:27 Pacific
Advisory Updated Date: 2024-04-15 12:00 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:
dnsmasq
Note:
This advisory is applicable to Amazon Linux 2 - Dnsmasq 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 dnsmasq to update your system.
aarch64:
dnsmasq-2.90-1.amzn2.0.1.aarch64
dnsmasq-utils-2.90-1.amzn2.0.1.aarch64
dnsmasq-debuginfo-2.90-1.amzn2.0.1.aarch64
src:
dnsmasq-2.90-1.amzn2.0.1.src
x86_64:
dnsmasq-2.90-1.amzn2.0.1.x86_64
dnsmasq-utils-2.90-1.amzn2.0.1.x86_64
dnsmasq-debuginfo-2.90-1.amzn2.0.1.x86_64