CVE-2017-17439

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    CVE-2017-17439

    Published: 6 Dec 2017Last Modified: 8 Jul 2026

    Summary:

    Details: In Heimdal through 7.4, remote unauthenticated attackers are able to crash the KDC by sending a crafted UDP packet containing empty data fields for client name or realm. The parser would unconditionally dereference NULL pointers in that case, leading to a segmentation fault. This is related to the _kdc_as_rep function in kdc/kerberos5.c and the der_length_visible_string function in lib/asn1/der_length.c.

    References: http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html, http://h5l.org/advisories.html?show=2017-12-08, http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html, https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887, https://www.debian.org/security/2017/dsa-4055, https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144, https://github.com/heimdal/heimdal/issues/353

    Affected packages

    Package

    Name:

    Purl:

    Affected ranges

    Type: GIT

    Events:

    Introduced- 0
    Fixed -None

    Affected versions

    heimdal-1.3.0pre1
    heimdal-1.3.0rc1
    heimdal-1.3.0pre11
    heimdal-1.3.0pre10
    heimdal-1.3.0pre9
    heimdal-1.3.0pre8
    heimdal-1.3.0pre7
    heimdal-1.3.0pre6
    heimdal-1.3.0pre5
    heimdal-1.3.0pre4
    heimdal-1.3.0pre3

    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