Rule Category

SERVER-OTHER -- Snort has detected traffic exploiting vulnerabilities in a server in the network.

Alert Message

SERVER-OTHER NTP crypto-NAK denial of service attempt

Rule Explanation

This event is generated when a denial of service attempt is detected in NTP crypto-NAK. Impact: Detection of a Denial of Service Attack Details: Ease of Attack:

What To Look For

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

MITRE ATT&CK Framework

Tactic:

Technique:

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

CVE

Rule Vulnerability

CVE Additional Information

CVE-2016-4957
ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-1547.
Details
Severity Base Score8.6
Impact Score4.0 Exploit Score3.9
Confidentiality ImpactNONE Integrity ImpactNONE
Availability ImpactHIGH Access Vector
Authentication Ease of Access