🛡️ CVE-2023-50387 — bind
Description
Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the "KeyTrap" issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records.
How this vulnerability can be exploited
This issue can be reached over the network, attack complexity is low, an attacker needs no privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality none, integrity none, availability high.
Weakness class
CVE-2023-50387 is classified as CWE-770: Allocation of Resources Without Limits. Resources are allocated on request with no cap, so a client can exhaust them.
Affected software
CVE-2023-50387 is recorded against 13 packages.
- bind (from 9.19.0 up to 9.19.20)
- dnsmasq (fixed in 2.90)
- enterprise-linux
- fedora
- knot-resolver (fixed in 5.71)
- recursor (from 5.0.0 up to 5.0.2)
- unbound (fixed in 1.19.1)
- windows-server-2008
- windows-server-2012
- windows-server-2016
- windows-server-2019
- windows-server-2022
- windows-server-2022-23h2
Timeline and source
Published on 14 February 2024 and last revised on 17 June 2026. No public exploit is currently recorded for this entry. A vendor advisory or fix has been published. Record sourced from NVD.
References
www.openwall.com
www.openwall.com
access.redhat.com
bugzilla.suse.com
docs.powerdns.com
gitlab.nic.cz
kb.isc.org
lists.debian.org
lists.debian.org
lists.fedoraproject.org
lists.fedoraproject.org
lists.fedoraproject.org
lists.fedoraproject.org
lists.fedoraproject.org
lists.fedoraproject.org
CVE-2023-50387 on other distributions
Each distribution ships its own build and its own fixed version. Pick the one you run:
Details
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| bind | 9.19.0 | 9.19.20 |
| dnsmasq | — | 2.90 |
| enterprise-linux | — | — |
| fedora | — | — |
| knot-resolver | — | 5.71 |
| recursor | 5.0.0 | 5.0.2 |
| unbound | — | 1.19.1 |
| windows-server-2008 | — | — |
| windows-server-2012 | — | — |
| windows-server-2016 | — | — |
| windows-server-2019 | — | — |
| windows-server-2022 | — | — |
| windows-server-2022-23h2 | — | — |
References
Similar Threats
- Unknown ALPINE-CVE-2023-50387
- Unknown ALPINE-CVE-2023-50868
- Unknown ALPINE-CVE-2023-4408
- Unknown ALPINE-CVE-2023-5517
- Unknown ALPINE-CVE-2023-3341
More CVE 2023 advisories
Browse all of CVE 2023 in the advisory index.
Site Security Check
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