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 excessive outbound NXDOMAIN replies - possible spoof of domain run by local DNS servers

Rule Explanation

The DNS protocol, as implemented in (1) BIND 8 and 9 before 9.5.0-P1, 9.4.2-P1, and 9.3.5-P1; (2) Microsoft DNS in Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP1 and SP2; and other implementations allow remote attackers to spoof DNS traffic via a birthday attack that uses in-bailiwick referrals to conduct cache poisoning against recursive resolvers, related to insufficient randomness of DNS transaction IDs and source ports, aka "DNS Insufficient Socket Entropy Vulnerability" or "the Kaminsky bug." Impact: CVSS base score 5.0 CVSS impact score 2.9 CVSS exploitability score 10.0 confidentialityImpact NONE integrityImpact PARTIAL availabilityImpact PARTIAL Details: Ease of Attack:

What To Look For

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].

MITRE ATT&CK Framework

Tactic:

Technique:

For reference, see the MITRE ATT&CK vulnerability types here: https://attack.mitre.org

CVE

Additional Links

Rule Vulnerability

CVE Additional Information

CVE-2008-1447
The DNS protocol, as implemented in (1) BIND 8 and 9 before 9.5.0-P1, 9.4.2-P1, and 9.3.5-P1; (2) Microsoft DNS in Windows 2000 SP4, XP SP2 and SP3, and Server 2003 SP1 and SP2; and other implementations allow remote attackers to spoof DNS traffic via a birthday attack that uses in-bailiwick referrals to conduct cache poisoning against recursive resolvers, related to insufficient randomness of DNS transaction IDs and source ports, aka "DNS Insufficient Socket Entropy Vulnerability" or "the Kaminsky bug."
Details
SeverityMEDIUM Base Score5.0
Impact Score2.9 Exploit Score10.0
Confidentiality ImpactNONE Integrity ImpactPARTIAL
Availability ImpactNONE Access Vector
AuthenticationNONE Ease of Access
CVE-2009-0233
The DNS Resolver Cache Service (aka DNSCache) in Windows DNS Server in Microsoft Windows 2000 SP4, Server 2003 SP1 and SP2, and Server 2008, when dynamic updates are enabled, does not reuse cached DNS responses in all applicable situations, which makes it easier for remote attackers to predict transaction IDs and poison caches by simultaneously sending crafted DNS queries and responses, aka "DNS Server Query Validation Vulnerability."
Details
SeverityMEDIUM Base Score5.8
Impact Score4.9 Exploit Score8.6
Confidentiality ImpactNONE Integrity ImpactPARTIAL
Availability ImpactPARTIAL Access Vector
AuthenticationNONE Ease of Access
CVE-2012-0006
The DNS server in Microsoft Windows Server 2003 SP2 and Server 2008 SP2, R2, and R2 SP1 does not properly handle objects in memory during record lookup, which allows remote attackers to cause a denial of service (daemon restart) via a crafted query, aka "DNS Denial of Service Vulnerability."
Details
SeverityMEDIUM Base Score5.0
Impact Score2.9 Exploit Score10.0
Confidentiality ImpactNONE Integrity ImpactNONE
Availability ImpactPARTIAL Access Vector
AuthenticationNONE Ease of Access