ALAS-2024-553

Amazon Linux 2023 Security Advisory: ALAS-2024-553
Advisory Release Date: 2024-02-29 10:29 Pacific
Advisory Updated Date: 2024-03-05 12:00 Pacific
Severity: Important
Issue Overview:

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


Issue Correction:
Run dnf update unbound --releasever 2023.3.20240304 to update your system.

New Packages:
aarch64:
    unbound-libs-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    python3-unbound-1.17.1-1.amzn2023.0.2.aarch64
    unbound-libs-1.17.1-1.amzn2023.0.2.aarch64
    unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-debugsource-1.17.1-1.amzn2023.0.2.aarch64
    unbound-utils-1.17.1-1.amzn2023.0.2.aarch64
    unbound-utils-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-anchor-1.17.1-1.amzn2023.0.2.aarch64
    unbound-devel-1.17.1-1.amzn2023.0.2.aarch64
    python3-unbound-debuginfo-1.17.1-1.amzn2023.0.2.aarch64
    unbound-1.17.1-1.amzn2023.0.2.aarch64

src:
    unbound-1.17.1-1.amzn2023.0.2.src

x86_64:
    unbound-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-utils-1.17.1-1.amzn2023.0.2.x86_64
    unbound-utils-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-libs-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    python3-unbound-1.17.1-1.amzn2023.0.2.x86_64
    unbound-1.17.1-1.amzn2023.0.2.x86_64
    unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    python3-unbound-debuginfo-1.17.1-1.amzn2023.0.2.x86_64
    unbound-debugsource-1.17.1-1.amzn2023.0.2.x86_64
    unbound-anchor-1.17.1-1.amzn2023.0.2.x86_64
    unbound-libs-1.17.1-1.amzn2023.0.2.x86_64
    unbound-devel-1.17.1-1.amzn2023.0.2.x86_64

Additional References

Red Hat: CVE-2023-50387, CVE-2023-50868

Mitre: CVE-2023-50387, CVE-2023-50868