CVE-2023-50868

Description

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.

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CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-400 Uncontrolled Resource Consumption

Affected Products

Vendor	Product	Versions
isc	bind	9.0.0 — 9.16.48
isc	bind	9.9.3 — 9.16.48
isc	bind	9.18.0 — 9.18.24
isc	bind	9.18.11 — 9.18.24
isc	bind	9.19.0 — 9.19.21
fedoraproject	fedora	All
fedoraproject	fedora	All
debian	debian_linux	All
debian	debian_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
redhat	enterprise_linux	All
powerdns	recursor	< 4.8.5
powerdns	recursor	4.9.0 — 4.9.3
powerdns	recursor	5.0.0 — 5.0.2
netapp	bootstrap_os	All
netapp	hci_compute_node	All
netapp	active_iq_unified_manager	All
netapp	hci_baseboard_management_controller	All
netapp	h300s	All
netapp	h410c	All
netapp	h410s	All
netapp	h500s	All
netapp	h700s	All

References

Advisories & Patches

Exploits

https://www.isc.org/blogs/2024-bind-security-release/ https://www.isc.org/blogs/2024-bind-security-release/

Other References

http://www.openwall.com/lists/oss-security/2024/02/16/2 http://www.openwall.com/lists/oss-security/2024/02/16/3 https://bugzilla.suse.com/show_bug.cgi?id=1219826 https://datatracker.ietf.org/doc/html/rfc5155 https://gitlab.nic.cz/knot/knot-resolver/-/releases/v5.7.1 https://kb.isc.org/docs/cve-2023-50868 https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html https://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released/ http://www.openwall.com/lists/oss-security/2024/02/16/2 http://www.openwall.com/lists/oss-security/2024/02/16/3

Frequently Asked Questions

What is CVE-2023-50868? +

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. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2023-50868? +

CVE-2023-50868 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2023-50868? +

CVE-2023-50868 affects products from debian, fedoraproject, isc, netapp, powerdns, redhat, specifically: active_iq_unified_manager, bind, bootstrap_os, debian_linux, enterprise_linux, fedora, h300s, h410c, h410s, h500s, h700s, hci_baseboard_management_controller, hci_compute_node, recursor. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2023-50868? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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