CVE-2024-8508 - CVE House
Back to Database
Status published Medium CVE-2024-8508

Unbounded name compression could lead to Denial of Service

Vulnerability 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

THREAT MONITOR

Am I Vulnerable?

Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2024-8508

Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • Toshifumi Sakaguchi

References

More from NLnet Labs

View All →
CVE-2025-5994
Cache poisoning via the ECS-enabled Rebirthday Attack
High 8.7
CVE-2025-11411
Possible domain hijacking via promiscuous records in the authority section
Medium 5.7
CVE-2025-0638
Routinator crashes when illegal characters are present in manifest file names
High 7.5
CVE-2024-1931
Denial of service when trimming EDE text on positive replies
High 7.5
CVE-2024-1622
Routinator terminates when RTR connection is reset too quickly after opening
High 7.5

Affected Vendor

Affected Software

Unbound
Vulnerable Versions:
0

Timeline

Official Publish: October 3rd, 2024
Last Modified: November 14th, 2024
Added to House: July 22nd, 2026

CVSS Vectors

V3: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

Weaknesses (CWE)

CWE-606

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.