CVE-2017-17439

7.5 HIGH
Published: December 06, 2017 Modified: May 13, 2026
View on NVD

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.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144
Source: cve@mitre.org
Issue Tracking Mailing List Third Party Advisory
https://github.com/heimdal/heimdal/issues/353
Source: cve@mitre.org
Patch Third Party Advisory
https://www.debian.org/security/2017/dsa-4055
Source: cve@mitre.org
Third Party Advisory
http://h5l.org/advisories.html?show=2017-12-08
Source: af854a3a-2127-422b-91ae-364da2661108
http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144
Source: af854a3a-2127-422b-91ae-364da2661108
Issue Tracking Mailing List Third Party Advisory
https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory
https://github.com/heimdal/heimdal/issues/353
Source: af854a3a-2127-422b-91ae-364da2661108
Patch Third Party Advisory
https://www.debian.org/security/2017/dsa-4055
Source: af854a3a-2127-422b-91ae-364da2661108
Third Party Advisory

14 reference(s) from NVD

Quick Stats

CVSS v3 Score
7.5 / 10.0
EPSS (Exploit Probability)
3.8%
88th percentile
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)

Affected Vendors

heimdal_project debian