Oracle Linux: CVE-2024-8508: ELSA-2024-11232: unbound:1.16.2 security update (MODERATE) (Multiple Advisories)

Oracle Linux: CVE-2024-8508: ELSA-2024-11232:unbound:1.16.2 security update (MODERATE) (Multiple Advisories)

Severity

5

CVSS

(AV:N/AC:L/Au:N/C:N/I:N/A:P)

Published

10/03/2024

Created

12/24/2024

Added

12/23/2024

Modified

02/06/2025

Description

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. A flaw was found in Unbound which can lead to degraded performance and an eventual denial of service when handling replies with very large RRsets that require name compression to be applied. Versions prior to 1.21.1 do not have a hard limit on the number of name compression calculations that Unbound can perform per packet, meaning that if a specially crafted query is passed for the contents of a malicious zone with very large RRsets, Unbound may spend a considerable amount of time applying name compression to downstream replies, locking the CPU until the whole packet has been processed.

Solution(s)

• oracle-linux-upgrade-python3-unbound
• oracle-linux-upgrade-unbound
• oracle-linux-upgrade-unbound-devel
• oracle-linux-upgrade-unbound-libs

References

• https://attackerkb.com/topics/cve-2024-8508
• CVE - 2024-8508
• ELSA-2024-11232
• ELSA-2025-0837