CVE-2017-17439
Heimdal KDC DoS Vulnerability
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.
INFO
Published Date :
Dec. 6, 2017, 3:29 p.m.
Last Modified :
April 20, 2025, 1:37 a.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 2.0 | MEDIUM | [email protected] | ||||
| CVSS 3.0 | HIGH | [email protected] |
Solution
- Update the Heimdal packages.
- Update the libheimdal packages.
Public PoC/Exploit Available at Github
CVE-2017-17439 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2017-17439.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2017-17439 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2017-17439
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2017-17439 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2017-17439 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference http://h5l.org/advisories.html?show=2017-12-08 Added Reference http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html Added Reference http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html Added Reference https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 Added Reference https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 Added Reference https://github.com/heimdal/heimdal/issues/353 Added Reference https://www.debian.org/security/2017/dsa-4055 -
CVE Modified by [email protected]
May. 14, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Dec. 30, 2017
Action Type Old Value New Value Added Reference http://www.h5l.org/pipermail/heimdal-announce/2017-December/000008.html [No Types Assigned] Added Reference http://h5l.org/advisories.html?show=2017-12-08 [No Types Assigned] -
Initial Analysis by [email protected]
Dec. 22, 2017
Action Type Old Value New Value Added CVSS V2 (AV:N/AC:L/Au:N/C:N/I:N/A:P) Added CVSS V3 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://github.com/heimdal/heimdal/issues/353 No Types Assigned https://github.com/heimdal/heimdal/issues/353 Patch, Third Party Advisory Changed Reference Type http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html No Types Assigned http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html Third Party Advisory Changed Reference Type https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 No Types Assigned https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=878144 Issue Tracking, Mailing List, Third Party Advisory Changed Reference Type https://www.debian.org/security/2017/dsa-4055 No Types Assigned https://www.debian.org/security/2017/dsa-4055 Third Party Advisory Changed Reference Type https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 No Types Assigned https://github.com/heimdal/heimdal/commit/1a6a6e462dc2ac6111f9e02c6852ddec4849b887 Third Party Advisory Added CWE CWE-476 Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:* Added CPE Configuration OR *cpe:2.3:a:heimdal_project:heimdal:*:*:*:*:*:*:*:* versions up to (including) 7.4.0 -
CVE Modified by [email protected]
Dec. 09, 2017
Action Type Old Value New Value Added Reference https://www.debian.org/security/2017/dsa-4055 [No Types Assigned] -
CVE Modified by [email protected]
Dec. 07, 2017
Action Type Old Value New Value Changed Description In Heimdal 7.1.0, 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. 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. Added Reference http://www.h5l.org/pipermail/heimdal-discuss/2017-August/000259.html [No Types Assigned]
Vulnerability Scoring Details
Base CVSS Score: 7.5
Base CVSS Score: 5
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
9.18 }} 0.05%
score
0.92406
percentile