Rule Category

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

Alert Message

SERVER-OTHER OpenSSL OCSP Status Request Extension denial of service attempt

Rule Explanation

Multiple memory leaks in t1_lib.c in OpenSSL before 1.0.1u, 1.0.2 before 1.0.2i, and 1.1.0 before 1.1.0a allow remote attackers to cause a denial of service (memory consumption) via large OCSP Status Request extensions. Impact: CVSS base score 7.5 CVSS impact score 3.6 CVSS exploitability score 3.9 confidentialityImpact NONE integrityImpact NONE availabilityImpact NONE Details: Ease of Attack:

What To Look For

Rule alerts when an attempt to trigger DoS with 100 OCSP status request packets sent within 10 seconds.

Known Usage

No public information

False Positives

No known false positives

Contributors

Cisco Talos Intelligence Group

Rule Groups

MITRE::ATT&CK Framework::Enterprise::Impact::Endpoint Denial of Service::Application or System Exploitation

MITRE::ATT&CK Framework::Enterprise::Initial Access::Exploit Public-Facing Application

CVE

Additional Links

Rule Vulnerability

Denial of Service

Denial of Service attacks aim to make a server or program unresponsive for users. These attacks may be volume-based, to overwhelm the system, or they may use certain logical flaws in the software to cut the service off from the users. The attack may come from one or multiple sources. These attacks do not usually lead to a remote code execution. Volume based attacks are best handled using a firewall application.

CVE Additional Information

This product uses data from the NVD API but is not endorsed or certified by the NVD.
CVE-2016-6304
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