SID 3:21355

Rule Category

PROTOCOL-DNS -- Snort alerted on a Domain Name Server (DNS) protocol issue. These packets travel over UDP on port 53 to serve DNS queries--user website requests through a browser. Several vulnerability use-cases exist (ie, additional data could be sent with a request, which would contact a DNS server pre-prepared to send information back and forth).

Alert Message

PROTOCOL-DNS potential dns cache poisoning attempt - mismatched txid

Rule Explanation

The DNS implementation in smtpsvc.dll before 6.0.2600.5949 in Microsoft Windows 2000 SP4 and earlier, Windows XP SP3 and earlier, Windows Server 2003 SP2 and earlier, Windows Server 2008 SP2 and earlier, Windows Server 2008 R2, Exchange Server 2003 SP3 and earlier, Exchange Server 2007 SP2 and earlier, and Exchange Server 2010 does not verify that transaction IDs of responses match transaction IDs of queries, which makes it easier for man-in-the-middle attackers to spoof DNS responses, a different vulnerability than CVE-2010-0024 and CVE-2010-0025.

What To Look For

The DNS implementation in smtpsvc.dll before 6.0.2600.5949 in Microsoft Windows 2000 SP4 and earlier, Windows XP SP3 and earlier, Windows Server 2003 SP2 and earlier, Windows Server 2008 SP2 and earlier, Windows Server 2008 R2, Exchange Server 2003 SP3 and earlier, Exchange Server 2007 SP2 and earlier, and Exchange Server 2010 does not verify that transaction IDs of responses match transaction IDs of queries, which makes it easier for man-in-the-middle attackers to spoof DNS responses, a different vulnerability than CVE-2010-0024 and CVE-2010-0025.

Known Usage

No public information

False Positives

No known false positives

Contributors

Talos research team. This document was generated from data supplied by the national vulnerability database, a product of the national institute of standards and technology. For more information see [nvd].