Rule Category

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

Alert Message

SERVER-OTHER OpenSSL invalid Diffie-Hellman parameter NULL pointer dereference attempt

Rule Explanation

This event is generated when an attacker attempts to exploit a NULL pointer dereference vulnerability present in OpenSSL. Impact: Detection of a Denial of Service Attack Details: Rule checks for attempts to exploit a NULL pointer dereference vulnerability present in OpenSSL. 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

CVE Additional Information

CVE-2017-3730
In OpenSSL 1.1.0 before 1.1.0d, if a malicious server supplies bad parameters for a DHE or ECDHE key exchange then this can result in the client attempting to dereference a NULL pointer leading to a client crash. This could be exploited in a Denial of Service attack.
Details
Severity Base Score7.5
Impact Score3.6 Exploit Score3.9
Confidentiality ImpactNONE Integrity ImpactNONE
Availability ImpactHIGH Access Vector
Authentication Ease of Access