CVE-2017-17439

Current Description

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.

Basic Data

PublishedDecember 06, 2017
Last ModifiedDecember 30, 2017
Assignercve@mitre.org
Data TypeCVE
Data FormatMITRE
Data Version4.0
Problem TypeCWE-476
CVE Data Version4.0

Base Metric V2

CVSS 2 - Version2.0
CVSS 2 - Vector StringAV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS 2 - Access VectorNETWORK
CVSS 2 - Access ComplexityLOW
CVSS 2 - AuthenticationNONE
CVSS 2 - Confidentiality ImpactNONE
CVSS 2 - Availability ImpactPARTIAL
CVSS 2 - Base Score5.0
SeverityMEDIUM
Exploitability Score10.0
Impact Score2.9
Obtain All Privilegefalse
Obtain User Privilegefalse
Obtain Other Privilegefalse

Base Metric V3

CVSS 3 - Version3.0
CVSS 3 - Vector StringCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 3 - Attack VectorNETWORK
CVSS 3 - Attack ComplexityLOW
CVSS 3 - Privileges RequiredNONE
CVSS 3 - User InteractionNONE
CVSS 3 - ScopeUNCHANGED
CVSS 3 - Confidentiality ImpactNONE
CVSS 3 - Integrity ImpactNONE
CVSS 3 - Availability ImpactHIGH
CVSS 3 - Base Score7.5
CVSS 3 - Base SeverityHIGH
Exploitability Score3.9
Base SeverityHIGH

Configurations

  • OR - Configuration 1
    Cpe VersionPartVendorProductVersionUpdateEditionLanguageSW EditionTarget SWTarget HWOtherVersion Start IncludingVersion End IncludingVersion Start ExcludingVersion End Excluding
    2.3OSDebianDebian Linux9.0*******
  • OR - Configuration 2
    Cpe VersionPartVendorProductVersionUpdateEditionLanguageSW EditionTarget SWTarget HWOtherVersion Start IncludingVersion End IncludingVersion Start ExcludingVersion End Excluding
    2.3ApplicationHeimdal ProjectHeimdal********7.4.0

Vulnerable Software List

VendorProductVersions
Debian Debian Linux 9.0
Heimdal Project Heimdal *

References

NameSourceURLTags
http://h5l.org/advisories.html?show=2017-12-08http://h5l.org/advisories.html?show=2017-12-08CONFIRM
http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.htmlhttp://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.htmlCONFIRM
http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.htmlhttp://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.htmlMISCThird Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144CONFIRMIssue Tracking Mailing List Third Party Advisory
https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887CONFIRMThird Party Advisory
https://github.com/heimdal/heimdal/issues/353https://github.com/heimdal/heimdal/issues/353CONFIRMPatch Third Party Advisory
DSA-4055https://www.debian.org/security/2017/dsa-4055DEBIANThird Party Advisory