CVE-2023-50868

bind9: Preparing an NSEC3 closest encloser proof can exhaust CPU resources

Severity Score

7.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

El aspecto Closest Encloser Proof del protocolo DNS (en RFC 5155 cuando se omite la guía RFC 9276) permite a atacantes remotos provocar una denegación de servicio (consumo de CPU para cálculos SHA-1) a través de respuestas DNSSEC en un ataque de subdominio aleatorio, también conocido como " Problema NSEC3". La especificación RFC 5155 implica que un algoritmo debe realizar miles de iteraciones de una función hash en determinadas situaciones.

A flaw was found in bind9. By flooding a DNSSEC resolver with responses coming from a DNSEC-signed zone using NSEC3, an attacker can lead the targeted resolver to a CPU exhaustion, further leading to a Denial of Service on the targeted host. This vulnerability applies only for systems where DNSSEC validation is enabled.

Multiple vulnerabilities have been discovered in Dnsmasq, the worst of which could lead to a denial of service. Versions greater than or equal to 2.90 are affected.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2023-12-14 CVE Reserved
2024-02-13 CVE Published
2024-02-19 EPSS Updated
2024-08-02 CVE Updated
2024-10-24 First Exploit
---------- Exploited in Wild
---------- KEV Due Date

CWE

CWE-400: Uncontrolled Resource Consumption

CAPEC

References (26)

URL	Tag	Source
http://www.openwall.com/lists/oss-security/2024/02/16/2	Mailing List
http://www.openwall.com/lists/oss-security/2024/02/16/3	Mailing List
https://bugzilla.suse.com/show_bug.cgi?id=1219826
https://datatracker.ietf.org/doc/html/rfc5155
https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2024-01.html
https://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1
https://kb.isc.org/docs/cve-2023-50868
https://lists.debian.org/debian-lts-announce/2024/02/msg00006.html	Mailing List
https://lists.debian.org/debian-lts-announce/2024/05/msg00011.html	Mailing List
https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html
https://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released
https://security.netapp.com/advisory/ntap-20240307-0008
https://www.isc.org/blogs/2024-bind-security-release

URL	Date	SRC
https://github.com/Goethe-Universitat-Cybersecurity/NSEC3-Encloser-Attack	2024-10-24

URL	Date	SRC

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2023-50868	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/6FV5O347JTX7P5OZA6NGO4MKTXRXMKOZ	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BUIP7T7Z4T3UHLXFWG6XIVDP4GYPD3AI	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/HVRDSJVZKMCXKKPP6PNR62T7RWZ3YSDZ	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/IGSLGKUAQTW5JPPZCMF5YPEYALLRUZZ6	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PNNHZSZPG2E7NBMBNYPGHCFI4V4XRWNQ	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RGS7JN6FZXUSTC2XKQHH27574XOULYYJ	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/SVYA42BLXUCIDLD35YIJPJSHDIADNYMP	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TEXGOYGW7DBS3N2QSSQONZ4ENIRQEAPG	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UQESRWMJCF4JEYJEAKLRM6CT55GLJAB7	2024-06-10
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/ZDZFMEKQTZ4L7RY46FCENWFB5MDT263R	2024-06-10
https://bugzilla.redhat.com/show_bug.cgi?id=2263917	2025-01-06

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Centos Search vendor "Centos"		Centos Search vendor "Centos" for product "Centos"				*		-		Affected
Oracle Search vendor "Oracle"		Exadata Dbserver Search vendor "Oracle" for product "Exadata Dbserver"				*		-		Affected
Oracle Search vendor "Oracle"		Linux Search vendor "Oracle" for product "Linux"				*		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Aus Search vendor "Redhat" for product "Rhel Aus"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel E4s Search vendor "Redhat" for product "Rhel E4s"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Eus Search vendor "Redhat" for product "Rhel Eus"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Tus Search vendor "Redhat" for product "Rhel Tus"				*		-		Affected
Alma Search vendor "Alma"		Linux Search vendor "Alma" for product "Linux"				*		-		Affected
Amazon Search vendor "Amazon"		Linux Search vendor "Amazon" for product "Linux"				*		-		Affected
Canonical Search vendor "Canonical"		Ubuntu Linux Search vendor "Canonical" for product "Ubuntu Linux"				*		-		Affected
Centos Search vendor "Centos"		Centos Search vendor "Centos" for product "Centos"				*		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				*		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				*		-		Affected
Freebsd Search vendor "Freebsd"		Freebsd Search vendor "Freebsd" for product "Freebsd"				*		-		Affected
Nutanix Search vendor "Nutanix"		Ahv Search vendor "Nutanix" for product "Ahv"				*		-		Affected
Nutanix Search vendor "Nutanix"		Aos Search vendor "Nutanix" for product "Aos"				*		-		Affected
Opensuse Search vendor "Opensuse"		Leap Search vendor "Opensuse" for product "Leap"				*		-		Affected
Oracle Search vendor "Oracle"		Linux Search vendor "Oracle" for product "Linux"				*		-		Affected
Redhat Search vendor "Redhat"		Enterprise Linux Search vendor "Redhat" for product "Enterprise Linux"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Aus Search vendor "Redhat" for product "Rhel Aus"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel E4s Search vendor "Redhat" for product "Rhel E4s"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Eus Search vendor "Redhat" for product "Rhel Eus"				*		-		Affected
Redhat Search vendor "Redhat"		Rhel Tus Search vendor "Redhat" for product "Rhel Tus"				*		-		Affected
Rocky Search vendor "Rocky"		Linux Search vendor "Rocky" for product "Linux"				*		-		Affected
Slackware Search vendor "Slackware"		Slackware Linux Search vendor "Slackware" for product "Slackware Linux"				*		-		Affected
Suse Search vendor "Suse"		Packagehub Search vendor "Suse" for product "Packagehub"				*		-		Affected
Suse Search vendor "Suse"		Sle-module-basesystem Search vendor "Suse" for product "Sle-module-basesystem"				*		-		Affected
Suse Search vendor "Suse"		Sle-module-server-applications Search vendor "Suse" for product "Sle-module-server-applications"				*		-		Affected
Suse Search vendor "Suse"		Sle-sdk Search vendor "Suse" for product "Sle-sdk"				*		-		Affected
Suse Search vendor "Suse"		Sle Hpc-espos Search vendor "Suse" for product "Sle Hpc-espos"				*		-		Affected
Suse Search vendor "Suse"		Sle Hpc-ltss Search vendor "Suse" for product "Sle Hpc-ltss"				*		-		Affected
Suse Search vendor "Suse"		Sle Hpc Search vendor "Suse" for product "Sle Hpc"				*		-		Affected
Suse Search vendor "Suse"		Sled Search vendor "Suse" for product "Sled"				*		-		Affected
Suse Search vendor "Suse"		Sles-ltss Search vendor "Suse" for product "Sles-ltss"				*		-		Affected
Suse Search vendor "Suse"		Sles Search vendor "Suse" for product "Sles"				*		-		Affected
Suse Search vendor "Suse"		Sles Sap Search vendor "Suse" for product "Sles Sap"				*		-		Affected
Suse Search vendor "Suse"		Suse-manager-proxy Search vendor "Suse" for product "Suse-manager-proxy"				*		-		Affected
Suse Search vendor "Suse"		Suse-manager-server Search vendor "Suse" for product "Suse-manager-server"				*		-		Affected