Microsoft Windows XP Windows NAT Helper ipnathlp.dll DNS Query null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability categorized as critical has been discovered in Microsoft Windows XP. Affected by this vulnerability is an unknown functionality in the library ipnathlp.dll of the component Windows NAT Helper Component. The manipulation as part of DNS Query results in null pointer dereference. This vulnerability is known as CVE-2006-5614. Furthermore, an exploit is available. It is advisable to use an alternative in place of the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Microsoft Windows XP (Operating System). Affected is an unknown functionality in the library ipnathlp.dll of the component Windows NAT Helper Component. The manipulation as part of a DNS Query leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

Microsoft Windows NAT Helper Components (ipnathlp.dll) on Windows XP SP2, when Internet Connection Sharing is enabled, allows remote attackers to cause a denial of service (svchost.exe crash) via a malformed DNS query, which results in a null pointer dereference.

The bug was discovered 10/28/2006. The weakness was published 10/30/2006 by h07 (Website). The advisory is shared for download at exploit-db.com. This vulnerability is traded as CVE-2006-5614 since 10/30/2006. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. Technical details and a public exploit are known.

A public exploit has been developed by h07 and been published even before and not after the advisory. The exploit is shared for download at exploit-db.com. It is declared as highly functional. The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $25k-$100k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 90359 (Windows ICS Denial of Service - Zero Day).

Applying a patch is able to eliminate this problem. The bugfix is ready for download at windowsupdate.microsoft.com. The problem might be mitigated by replacing the product with as an alternative. The best possible mitigation is suggested to be establishing an alternative product. Attack attempts may be identified with Snort ID 8710. In this case the pattern |00 00 00 00 00 00 00 00| is used for detection. Furthermore it is possible to detect and prevent this kind of attack with TippingPoint and the filter 9975.

The vulnerability is also documented in the databases at X-Force (29917), Exploit-DB (2672), SecurityFocus (BID 20804†), OSVDB (30096†) and Secunia (SA22592†). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

Vendor

Name

Version

License

Support

  • end of life (old version)

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.9
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.9
VulDB Temp Score: 5.5
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

NVD Base Score: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: No
Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Highly functional
Author: h07
Download: 🔍

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Qualys ID: 🔍
Qualys Name: 🔍

MetaSploit ID: nat_helper.rb
MetaSploit Name: Microsoft Windows NAT Helper Denial of Service
MetaSploit File: 🔍

Exploit-DB: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Alternative
Status: 🔍

0-Day Time: 🔍

Patch: windowsupdate.microsoft.com

Snort ID: 8710
Snort Message: DNS Windows NAT helper components udp denial of service attempt
Snort Pattern: 🔍
TippingPoint: 🔍
SourceFire IPS: 🔍
PaloAlto IPS: 🔍
Fortigate IPS: 🔍

Timelineinfo

10/28/2006 🔍
10/28/2006 +0 days 🔍
10/28/2006 +0 days 🔍
10/28/2006 +0 days 🔍
10/30/2006 +2 days 🔍
10/30/2006 +0 days 🔍
10/30/2006 +0 days 🔍
10/30/2006 +0 days 🔍
10/30/2006 +0 days 🔍
10/30/2006 +0 days 🔍
10/30/2006 +0 days 🔍
10/31/2006 +0 days 🔍
11/07/2006 +7 days 🔍
04/25/2026 +7109 days 🔍

Sourcesinfo

Vendor: microsoft.com
Product: microsoft.com

Advisory: exploit-db.com
Researcher: h07
Status: Confirmed

CVE: CVE-2006-5614 (🔍)
GCVE (CVE): GCVE-0-2006-5614
GCVE (VulDB): GCVE-100-2640
X-Force: 29917 - Microsoft Windows XP NAT Helper ipnathlp.dll denial of service, Medium Risk
SecurityFocus: 20804 - Microsoft Windows NAT Helper Remote Denial of Service Vulnerability
Secunia: 22592 - Microsoft Windows Internet Connection Sharing Denial of Service, Less Critical
OSVDB: 30096 - Microsoft Windows NAT Helper Components ipnathlp.dll with ICS Malformed DNS Query DoS
SecurityTracker: 1017133
Vulnerability Center: 13070 - Microsoft Windows NAT Helper Components With Internet Connection Sharing Enabled Denial of Service, Medium
Vupen: ADV-2006-4248

scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 10/31/2006 13:10
Updated: 04/25/2026 23:01
Changes: 10/31/2006 13:10 (104), 07/10/2019 16:40 (1), 08/03/2024 09:22 (17), 06/15/2025 19:22 (7), 04/25/2026 23:01 (2)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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