5.3
MEDIUM
CVE-2024-8508
Unbound Denial of Service and Performance 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.

INFO

Published Date :

Oct. 3, 2024, 5:15 p.m.

Last Modified :

Dec. 17, 2024, 7:28 p.m.

Remotely Exploitable :

Yes !

Impact Score :

1.4

Exploitability Score :

3.9
Affected Products

The following products are affected by CVE-2024-8508 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Debian debian_linux
1 Nlnetlabs unbound
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2024-8508.

URL Resource
https://www.nlnetlabs.nl/downloads/unbound/CVE-2024-8508.txt Vendor Advisory
http://www.openwall.com/lists/oss-security/2024/10/04/5 Mailing List Third Party Advisory
https://lists.debian.org/debian-lts-announce/2024/11/msg00009.html Mailing List Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2024-8508 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2024-8508 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Dec. 17, 2024

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
    Added CWE NIST CWE-1284
    Added CPE Configuration OR *cpe:2.3:a:nlnetlabs:unbound:*:*:*:*:*:*:*:* versions up to (excluding) 1.21.1
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
    Changed Reference Type http://www.openwall.com/lists/oss-security/2024/10/04/5 No Types Assigned http://www.openwall.com/lists/oss-security/2024/10/04/5 Mailing List, Third Party Advisory
    Changed Reference Type https://lists.debian.org/debian-lts-announce/2024/11/msg00009.html No Types Assigned https://lists.debian.org/debian-lts-announce/2024/11/msg00009.html Mailing List, Third Party Advisory
    Changed Reference Type https://www.nlnetlabs.nl/downloads/unbound/CVE-2024-8508.txt No Types Assigned https://www.nlnetlabs.nl/downloads/unbound/CVE-2024-8508.txt Vendor Advisory
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference http://www.openwall.com/lists/oss-security/2024/10/04/5
    Added Reference https://lists.debian.org/debian-lts-announce/2024/11/msg00009.html
  • CVE Received by [email protected]

    Oct. 03, 2024

    Action Type Old Value New Value
    Added 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.
    Added Reference NLnet Labs https://www.nlnetlabs.nl/downloads/unbound/CVE-2024-8508.txt [No types assigned]
    Added CWE NLnet Labs CWE-606
    Added CVSS V3.1 NLnet Labs AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2024-8508 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2024-8508 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability