SID 3:34051

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 Cisco ASA memory exhaustion denial of service attempt

Rule Explanation

The DNS implementation in Cisco Adaptive Security Appliance (ASA) Software 7.2 before 7.2(5.16), 8.2 before 8.2(5.57), 8.3 before 8.3(2.44), 8.4 before 8.4(7.28), 8.5 before 8.5(1.24), 8.6 before 8.6(1.17), 8.7 before 8.7(1.16), 9.0 before 9.0(4.33), 9.1 before 9.1(6.1), 9.2 before 9.2(3.4), and 9.3 before 9.3(3) allows man-in-the-middle attackers to cause a denial of service (memory consumption or device outage) by triggering outbound DNS queries and then sending crafted responses to these queries, aka Bug ID CSCuq77655. Impact: CVSS base score 7.1 CVSS impact score 6.9 CVSS exploitability score 8.6 confidentialityImpact NONE integrityImpact NONE availabilityImpact NONE Details: Ease of Attack:

What To Look For

No information provided

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].