National Vulnerability Database

National Vulnerability Database

National Vulnerability
Database

CVE-2017-17439 Detail

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.

Source:  MITRE
View Analysis Description

Impact

CVSS v3.0 Severity and Metrics:

Base Score: 7.5 HIGH
Vector: AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H (V3.0 legend)
Impact Score: 3.6
Exploitability Score: 3.9


Attack Vector (AV): Network
Attack Complexity (AC): Low
Privileges Required (PR): None
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

CVSS v2.0 Severity and Metrics:

Base Score: 5.0 MEDIUM
Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P) (V2 legend)
Impact Subscore: 2.9
Exploitability Subscore: 10.0


Access Vector (AV): Network
Access Complexity (AC): Low
Authentication (AU): None
Confidentiality (C): None
Integrity (I): None
Availability (A): Partial
Additional Information:
Allows disruption of service

References to Advisories, Solutions, and Tools

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Hyperlink Resource
http://h5l.org/advisories.html?show=2017-12-08
http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html
http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html Third Party Advisory
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 Issue Tracking Mailing List Third Party Advisory
https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 Third Party Advisory
https://github.com/heimdal/heimdal/issues/353 Patch Third Party Advisory
https://www.debian.org/security/2017/dsa-4055 Third Party Advisory

Technical Details

Vulnerability Type (View All)

  • NULL Pointer Dereference (CWE-476)

Known Affected Software Configurations Switch to CPE 2.2

Configuration 1 ( hide )
 cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*
     Show Matching CPE(s)

Configuration 2 ( hide )
 cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*
     Show Matching CPE(s)
Up to (including)
7.4.0


Change History

4 change records found - show changes

Quick Info

CVE Dictionary Entry:
CVE-2017-17439
NVD Published Date:
12/06/2017
NVD Last Modified:
12/29/2017