Rule Category

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

Alert Message

SERVER-OTHER NTP crypto-NAK packet flood attempt

Rule Explanation

Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication. Impact: CVSS base score 9.8 CVSS impact score 5.9 CVSS exploitability score 3.9 confidentialityImpact HIGH integrityImpact HIGH availabilityImpact HIGH 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

Rule Vulnerability

CVE Additional Information

CVE-2015-7871
Crypto-NAK packets in ntpd in NTP 4.2.x before 4.2.8p4, and 4.3.x before 4.3.77 allows remote attackers to bypass authentication.
Details
Severity Base Score9.8
Impact Score5.9 Exploit Score3.9
Confidentiality ImpactHIGH Integrity ImpactHIGH
Availability ImpactHIGH Access Vector
Authentication Ease of Access
CVE-2016-1550
An exploitable vulnerability exists in the message authentication functionality of libntp in ntp 4.2.8p4 and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92. An attacker can send a series of crafted messages to attempt to recover the message digest key.
Details
Severity Base Score5.3
Impact Score1.4 Exploit Score3.9
Confidentiality ImpactLOW Integrity ImpactNONE
Availability ImpactNONE Access Vector
Authentication Ease of Access