• Articles
    • Editorial Articles
    • Research Articles
    • WatchGuard Articles
  • The 443 Podcast
  • Threat Landscape
  • About
    • About Us
    • Contact Us
    • Contribute to Secplicity

Secplicity - Security Simplified

Powered by WatchGuard Technologies

Microsoft DNS Server NAPTR Code Execution Vulnerability

August 10, 2011 By Corey Nachreiner

Severity: High

9 August, 2011

Summary:

  • This vulnerability affects: The DNS service that ships with the Server versions of Windows
  • How an attacker exploits it: By sending specially crafted DNS queries
  • Impact: In the worst case, an attacker gains complete control of your DNS server
  • What to do: Deploy the appropriate Windows  update immediately, or let Windows Automatic Update do it for you

Exposure:

The Server versions of Windows ships with a DNS Server to allow administrators to offer Domain Name System services on their networks.

In a security bulletin released today as part of Patch Day, Microsoft describes two vulnerabilities that affects the DNS Server that ships with Server versions of Windows. While this is technically a Windows flaw, which we typically include in a combined Windows alert, we feel that it deserves individual attention due to its high severity.

The worst of the two issues is a remote code execution flaw involving the way the DNS server handles specially crafted Naming Authority Pointer (NAPTR) DNS resource records (RR). By sending a specially crafted NAPTR query to your DNS server, and attacker could exploit this vulnerability to gain complete control of your server. However, the attacker would have to own the malicious domain name, and the authoritative DNS server for that domain name, in order for this attack to succeed. Despite this slight mitigating factor, the DNS server vulnerability poses a serious risk to your network. You should patch your Microsoft DNS servers immediately.

The DNS Server also suffers from a less serious  Denial of Service (DoS) flaw, which an attacker could exploit to cause your DNS server to stop responding. If an attacker can prevent your users from accessing DNS services, they essentially prevent access to the Internet (by making it difficult for users to find resources by name).

Solution Path:

Download, test, and deploy the appropriate DNS server patches immediately, or let Windows Automatic Update do it for you.

  • For Windows Server 2003 (w/SP2)
  • For Windows Server 2003 x64 (w/SP2)
  • For Windows Server 2003 Itanium (w/SP2)
  • For Windows Server 2008 (w/SP2)
  • For Windows Server 2008 x64 (w/SP2)
  • For Windows Server R2 2008 Itanium

For All WatchGuard Users:

This attack leverages seemingly normal DNS traffic. You should apply the updates above.

Status:

Microsoft has released patches to fix this vulnerability

References:

  • MS Security Bulletin MS11-058

This alert was researched and written by Corey Nachreiner, CISSP.


What did you think of this alert? Let us know at [email protected].

More alerts and articles: Log into the LiveSecurity Archive.

Share This:

Related

Filed Under: Security Bytes Tagged With: code execution, dns, DNS Server, NAPTR, Updates and patches

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

The 443 Podcast

A weekly podcast featuring the leading white-hat hackers and security researchers. Listen Now
the 443 podcast

Threat Landscape

Filter and view Firebox Feed data by type of attack, region, country, and date range. View Now
threat landscape

Top Posts

  • Cybersecurity News: Free Cybersecurity Training, TrickBot Group Exposed, Major GoDaddy Breach, and Russia to Legalize cybercrime?!
  • US National Cybersecurity Strategy
  • Here Come The Regulations
  • Cybersecurity’s Toll on Mental Health

Email Newsletter

Sign up to get the latest security news and threat analysis delivered straight to your inbox

By signing up you agree to our Privacy Policy.


The views and opinions expressed on this website are those of the authors and do not necessarily reflect the policy or position of WatchGuard Technologies.

Stay in Touch

Recent Posts

  • Cybersecurity News: LastPass Incident Revealed, White House Issues Cybersecurity Strategy, FBI Purchases Leaked USHOR PII Data, and a Slew of Other Breaches
  • An Update on Section 230
  • Here Come The Regulations
  • US National Cybersecurity Strategy
  • Cybersecurity News: Free Cybersecurity Training, TrickBot Group Exposed, Major GoDaddy Breach, and Russia to Legalize cybercrime?!
View All

Search

Archives

Copyright © 2023 WatchGuard Technologies · Cookie Policy · Privacy Policy · Terms of Use