Amazon Linux 2023 Security Advisory: ALAS-2024-719
Advisory Release Date: 2024-10-10 03:02 Pacific
Advisory Updated Date: 2024-10-14 16:00 Pacific
NLnet Labs Unbound up to and including version 1.21.0 contains a vulnerability when handling replies with very large RRsets that it needs to perform name compression for. Malicious upstreams responses with very large RRsets can cause Unbound to spend a considerable time applying name compression to downstream replies. This can lead to degraded performance and eventually denial of service in well orchestrated attacks. The vulnerability can be exploited by a malicious actor querying Unbound for the specially crafted contents of a malicious zone with very large RRsets. Before Unbound replies to the query it will try to apply name compression which was an unbounded operation that could lock the CPU until the whole packet was complete. Unbound version 1.21.1 introduces a hard limit on the number of name compression calculations it is willing to do per packet. Packets that need more compression will result in semi-compressed packets or truncated packets, even on TCP for huge messages, to avoid locking the CPU for long. This change should not affect normal DNS traffic. (CVE-2024-8508)
Affected Packages:
unbound
Issue Correction:
Run dnf update unbound --releasever 2023.6.20241010 to update your system.
aarch64:
unbound-debuginfo-1.17.1-1.amzn2023.0.6.aarch64
python3-unbound-1.17.1-1.amzn2023.0.6.aarch64
unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.6.aarch64
python3-unbound-debuginfo-1.17.1-1.amzn2023.0.6.aarch64
unbound-1.17.1-1.amzn2023.0.6.aarch64
unbound-utils-debuginfo-1.17.1-1.amzn2023.0.6.aarch64
unbound-utils-1.17.1-1.amzn2023.0.6.aarch64
unbound-libs-debuginfo-1.17.1-1.amzn2023.0.6.aarch64
unbound-devel-1.17.1-1.amzn2023.0.6.aarch64
unbound-anchor-1.17.1-1.amzn2023.0.6.aarch64
unbound-libs-1.17.1-1.amzn2023.0.6.aarch64
unbound-debugsource-1.17.1-1.amzn2023.0.6.aarch64
src:
unbound-1.17.1-1.amzn2023.0.6.src
x86_64:
unbound-debuginfo-1.17.1-1.amzn2023.0.6.x86_64
unbound-utils-debuginfo-1.17.1-1.amzn2023.0.6.x86_64
unbound-anchor-debuginfo-1.17.1-1.amzn2023.0.6.x86_64
unbound-debugsource-1.17.1-1.amzn2023.0.6.x86_64
unbound-devel-1.17.1-1.amzn2023.0.6.x86_64
unbound-libs-debuginfo-1.17.1-1.amzn2023.0.6.x86_64
python3-unbound-debuginfo-1.17.1-1.amzn2023.0.6.x86_64
unbound-libs-1.17.1-1.amzn2023.0.6.x86_64
unbound-anchor-1.17.1-1.amzn2023.0.6.x86_64
unbound-1.17.1-1.amzn2023.0.6.x86_64
unbound-utils-1.17.1-1.amzn2023.0.6.x86_64
python3-unbound-1.17.1-1.amzn2023.0.6.x86_64