CVE-2017-17439

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.

CVSS v3.0 7.5 HIGH
CVSS v2.0 5.0 MEDIUM

7.5^/10

CVSS v3.0 : HIGH

Vector : AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Exploitability : 3.9 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

5.0^/10

CVSS v2.0 : MEDIUM

Vector : AV:N/AC:L/Au:N/C:N/I:N/A:P

Exploitability : 10.0 / Impact : 2.9

Access Vector NETWORK

Access Complexity LOW

Authentication NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact PARTIAL

References

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

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Configurations

Configuration 1 (hide)

cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*

Configuration 2 (hide)

cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:*

Information

Published : 2017-12-06 07:29

Updated : 2017-12-29 18:29

NVD link : CVE-2017-17439

Mitre link : CVE-2017-17439

JSON object : View

CWE

CWE-476

NULL Pointer Dereference

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Products Affected

debian

debian_linux

heimdal_project

heimdal

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