CVE Vulnerabilities

CVE-2023-50868

Uncontrolled Resource Consumption

Published: Feb 14, 2024 | Modified: May 12, 2025
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
7.5 IMPORTANT
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Ubuntu
MEDIUM

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.

Weakness

The product does not properly control the allocation and maintenance of a limited resource, thereby enabling an actor to influence the amount of resources consumed, eventually leading to the exhaustion of available resources.

Affected Software

Name Vendor Start Version End Version
Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION RedHat bind-32:9.8.2-0.68.rc1.el6_10.14 *
Red Hat Enterprise Linux 6 Extended Lifecycle Support - EXTENSION RedHat bind-dyndb-ldap-0:2.3-8.el6_10.1 *
Red Hat Enterprise Linux 7 RedHat bind-32:9.11.4-26.P2.el7_9.16 *
Red Hat Enterprise Linux 7 RedHat bind-dyndb-ldap-0:11.1-7.el7_9.1 *
Red Hat Enterprise Linux 7 RedHat dhcp-12:4.2.5-83.el7_9.2 *
Red Hat Enterprise Linux 7 Extended Lifecycle Support RedHat unbound-0:1.6.6-5.el7_9.1 *
Red Hat Enterprise Linux 8 RedHat unbound-0:1.16.2-5.el8_9.2 *
Red Hat Enterprise Linux 8 RedHat dnsmasq-0:2.79-31.el8_9.2 *
Red Hat Enterprise Linux 8 RedHat bind9.16-32:9.16.23-0.16.el8_9.2 *
Red Hat Enterprise Linux 8 RedHat bind-32:9.11.36-11.el8_9.1 *
Red Hat Enterprise Linux 8 RedHat bind-32:9.11.36-14.el8_10 *
Red Hat Enterprise Linux 8 RedHat bind-32:9.11.36-11.el8_9.1 *
Red Hat Enterprise Linux 8 RedHat bind-32:9.11.36-14.el8_10 *
Red Hat Enterprise Linux 8.2 Advanced Update Support RedHat unbound-0:1.7.3-12.el8_2.1 *
Red Hat Enterprise Linux 8.2 Advanced Update Support RedHat bind-32:9.11.13-6.el8_2.7 *
Red Hat Enterprise Linux 8.2 Advanced Update Support RedHat dhcp-12:4.3.6-40.el8_2.3 *
Red Hat Enterprise Linux 8.2 Advanced Update Support RedHat dnsmasq-0:2.79-11.el8_2.3 *
Red Hat Enterprise Linux 8.2 Telecommunications Update Service RedHat unbound-0:1.7.3-12.el8_2.1 *
Red Hat Enterprise Linux 8.2 Update Services for SAP Solutions RedHat unbound-0:1.7.3-12.el8_2.1 *
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support RedHat unbound-0:1.7.3-15.el8_4.1 *
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support RedHat bind-32:9.11.26-4.el8_4.4 *
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support RedHat dhcp-12:4.3.6-44.el8_4.3 *
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support RedHat dnsmasq-0:2.79-15.el8_4.2 *
Red Hat Enterprise Linux 8.4 Telecommunications Update Service RedHat unbound-0:1.7.3-15.el8_4.1 *
Red Hat Enterprise Linux 8.4 Telecommunications Update Service RedHat bind-32:9.11.26-4.el8_4.4 *
Red Hat Enterprise Linux 8.4 Telecommunications Update Service RedHat dhcp-12:4.3.6-44.el8_4.3 *
Red Hat Enterprise Linux 8.4 Telecommunications Update Service RedHat dnsmasq-0:2.79-15.el8_4.2 *
Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions RedHat unbound-0:1.7.3-15.el8_4.1 *
Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions RedHat bind-32:9.11.26-4.el8_4.4 *
Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions RedHat dhcp-12:4.3.6-44.el8_4.3 *
Red Hat Enterprise Linux 8.4 Update Services for SAP Solutions RedHat dnsmasq-0:2.79-15.el8_4.2 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat dnsmasq-0:2.79-21.el8_6.5 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat bind9.16-32:9.16.23-0.7.el8_6.5 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat unbound-0:1.7.3-17.el8_6.4 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat bind-32:9.11.36-3.el8_6.7 *
Red Hat Enterprise Linux 8.6 Extended Update Support RedHat dhcp-12:4.3.6-47.el8_6.2 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat unbound-0:1.16.2-5.el8_8.1 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat dnsmasq-0:2.79-26.el8_8.4 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat bind9.16-32:9.16.23-0.14.el8_8.4 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat bind-32:9.11.36-8.el8_8.4 *
Red Hat Enterprise Linux 8.8 Extended Update Support RedHat dhcp-12:4.3.6-49.el8_8.1 *
Red Hat Enterprise Linux 9 RedHat unbound-0:1.16.2-3.el9_3.1 *
Red Hat Enterprise Linux 9 RedHat dnsmasq-0:2.85-14.el9_3.1 *
Red Hat Enterprise Linux 9 RedHat bind-32:9.16.23-14.el9_3.4 *
Red Hat Enterprise Linux 9 RedHat bind-dyndb-ldap-0:11.9-8.el9_3.3 *
Red Hat Enterprise Linux 9 RedHat bind-32:9.16.23-18.el9_4.1 *
Red Hat Enterprise Linux 9 RedHat bind-dyndb-ldap-0:11.9-9.el9_4 *
Red Hat Enterprise Linux 9.0 Extended Update Support RedHat dnsmasq-0:2.85-3.el9_0.1 *
Red Hat Enterprise Linux 9.0 Extended Update Support RedHat bind-32:9.16.23-1.el9_0.5 *
Red Hat Enterprise Linux 9.0 Extended Update Support RedHat bind-dyndb-ldap-0:11.9-7.el9_0.1 *
Red Hat Enterprise Linux 9.0 Extended Update Support RedHat unbound-0:1.13.1-13.el9_0.4 *
Red Hat Enterprise Linux 9.2 Extended Update Support RedHat unbound-0:1.16.2-3.el9_2.1 *
Red Hat Enterprise Linux 9.2 Extended Update Support RedHat dnsmasq-0:2.85-6.el9_2.3 *
Red Hat Enterprise Linux 9.2 Extended Update Support RedHat bind-32:9.16.23-11.el9_2.4 *
Red Hat Enterprise Linux 9.2 Extended Update Support RedHat bind-dyndb-ldap-0:11.9-8.el9_2.2 *
Bind9 Ubuntu bionic *
Bind9 Ubuntu devel *
Bind9 Ubuntu esm-infra/bionic *
Bind9 Ubuntu esm-infra/xenial *
Bind9 Ubuntu focal *
Bind9 Ubuntu jammy *
Bind9 Ubuntu mantic *
Bind9 Ubuntu noble *
Bind9 Ubuntu oracular *
Bind9 Ubuntu plucky *
Bind9 Ubuntu trusty *
Bind9 Ubuntu trusty/esm *
Bind9 Ubuntu upstream *
Bind9 Ubuntu xenial *
Bind9-libs Ubuntu focal *
Dnsmasq Ubuntu bionic *
Dnsmasq Ubuntu devel *
Dnsmasq Ubuntu esm-infra/bionic *
Dnsmasq Ubuntu esm-infra/xenial *
Dnsmasq Ubuntu focal *
Dnsmasq Ubuntu jammy *
Dnsmasq Ubuntu mantic *
Dnsmasq Ubuntu noble *
Dnsmasq Ubuntu oracular *
Dnsmasq Ubuntu plucky *
Dnsmasq Ubuntu trusty *
Dnsmasq Ubuntu trusty/esm *
Dnsmasq Ubuntu upstream *
Dnsmasq Ubuntu xenial *
Isc-dhcp Ubuntu mantic *
Knot-resolver Ubuntu bionic *
Knot-resolver Ubuntu focal *
Knot-resolver Ubuntu mantic *
Knot-resolver Ubuntu upstream *
Knot-resolver Ubuntu xenial *
Pdns-recursor Ubuntu bionic *
Pdns-recursor Ubuntu focal *
Pdns-recursor Ubuntu mantic *
Pdns-recursor Ubuntu trusty *
Pdns-recursor Ubuntu upstream *
Pdns-recursor Ubuntu xenial *
Unbound Ubuntu bionic *
Unbound Ubuntu devel *
Unbound Ubuntu focal *
Unbound Ubuntu jammy *
Unbound Ubuntu mantic *
Unbound Ubuntu noble *
Unbound Ubuntu oracular *
Unbound Ubuntu plucky *
Unbound Ubuntu trusty *
Unbound Ubuntu trusty/esm *
Unbound Ubuntu upstream *
Unbound Ubuntu xenial *

Extended Description

Limited resources include memory, file system storage, database connection pool entries, and CPU. If an attacker can trigger the allocation of these limited resources, but the number or size of the resources is not controlled, then the attacker could cause a denial of service that consumes all available resources. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system. There are at least three distinct scenarios which can commonly lead to resource exhaustion:

Resource exhaustion problems are often result due to an incorrect implementation of the following situations:

Potential Mitigations

  • Mitigation of resource exhaustion attacks requires that the target system either:

  • The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.

  • The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

References