UBUNTU-CVE-2023-50868

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    UBUNTU-CVE-2023-50868

    Published: 13 Feb 2024Last Modified: 6 Oct 2026
    Upstream:
    CVE-2023-50868
    Aliases:
    USN-6633-1
    USN-6642-1
    USN-6657-1

    Summary:

    Details: 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.

    References: https://ubuntu.com/security/CVE-2023-50868, https://kb.isc.org/docs/cve-2023-50868, https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2024q1/017430.html, https://www.knot-resolver.cz/2024-02-13-knot-resolver-5.7.1.html, https://blog.powerdns.com/2024/02/13/powerdns-recursor-4-8-6-4-9-3-5-0-2-released, https://nlnetlabs.nl/news/2024/Feb/13/unbound-1.19.1-released/, https://nlnetlabs.nl/downloads/unbound/CVE-2023-50387_CVE-2023-50868.txt, https://ubuntu.com/security/notices/USN-6633-1, https://ubuntu.com/security/notices/USN-6642-1, https://ubuntu.com/security/notices/USN-6657-1, https://ubuntu.com/security/notices/USN-6665-1, https://ubuntu.com/security/notices/USN-6723-1, https://www.cve.org/CVERecord?id=CVE-2023-50868, https://ubuntu.com/security/notices/USN-6657-2

    Affected packages

    Package

    Name: bind9

    Purl: pkg:deb/ubuntu/bind9?arch=source&distro=trusty%2Fesm

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1:9.9.5.dfsg-3ubuntu0.19+esm12

    Affected versions

    1:9.9.3.dfsg.P2-4ubuntu1
    1:9.9.3.dfsg.P2-4ubuntu2
    1:9.9.3.dfsg.P2-4ubuntu3
    1:9.9.5.dfsg-2
    1:9.9.5.dfsg-3
    1:9.9.5.dfsg-3ubuntu0.1
    1:9.9.5.dfsg-3ubuntu0.2
    1:9.9.5.dfsg-3ubuntu0.3
    1:9.9.5.dfsg-3ubuntu0.4
    1:9.9.5.dfsg-3ubuntu0.5
    1:9.9.5.dfsg-3ubuntu0.6
    1:9.9.5.dfsg-3ubuntu0.7
    1:9.9.5.dfsg-3ubuntu0.8
    1:9.9.5.dfsg-3ubuntu0.9
    1:9.9.5.dfsg-3ubuntu0.10
    1:9.9.5.dfsg-3ubuntu0.11
    1:9.9.5.dfsg-3ubuntu0.12
    1:9.9.5.dfsg-3ubuntu0.13
    1:9.9.5.dfsg-3ubuntu0.14
    1:9.9.5.dfsg-3ubuntu0.15
    1:9.9.5.dfsg-3ubuntu0.16
    1:9.9.5.dfsg-3ubuntu0.17
    1:9.9.5.dfsg-3ubuntu0.18
    1:9.9.5.dfsg-3ubuntu0.19
    1:9.9.5.dfsg-3ubuntu0.19+esm1
    1:9.9.5.dfsg-3ubuntu0.19+esm2
    1:9.9.5.dfsg-3ubuntu0.19+esm3
    1:9.9.5.dfsg-3ubuntu0.19+esm4
    1:9.9.5.dfsg-3ubuntu0.19+esm5
    1:9.9.5.dfsg-3ubuntu0.19+esm6
    1:9.9.5.dfsg-3ubuntu0.19+esm7
    1:9.9.5.dfsg-3ubuntu0.19+esm9
    1:9.9.5.dfsg-3ubuntu0.19+esm10
    1:9.9.5.dfsg-3ubuntu0.19+esm11

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2023-50868 | CVE-DB