CVE-2018-20217

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    CVE-2018-20217

    Published: 26 Dec 2018Last Modified: 8 Jul 2026

    Summary:

    Details: A Reachable Assertion issue was discovered in the KDC in MIT Kerberos 5 (aka krb5) before 1.17. If an attacker can obtain a krbtgt ticket using an older encryption type (single-DES, triple-DES, or RC4), the attacker can crash the KDC by making an S4U2Self request.

    References: https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2KNHELH4YHNT6H2ESJWX2UIDXLBNGB2O/, https://lists.debian.org/debian-lts-announce/2019/01/msg00020.html, https://lists.debian.org/debian-lts-announce/2021/09/msg00019.html, https://security.netapp.com/advisory/ntap-20190416-0006/, http://krbdev.mit.edu/rt/Ticket/Display.html?id=8763, https://github.com/krb5/krb5/commit/5e6d1796106df8ba6bc1973ee0917c170d929086

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -97e3c42b2a89a2ec60eb93d3f974769e3e3cbdc5

    Affected versions

    krb5-1.17-beta2

    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