This signature detects an attempt to read the contents of the RAM of a system running a vulnerable version of OpenSSL, aka the Heartbleed attack. This signature detects a larger than expected amount of heartbeat data being returned by a web server. This vulnerability is further documented as CVE-2014-0160.
Use of this signature may cause a negative performance impact on the sensor. Event action filters should be used to exclude IP addresses the signature alerts on that are not running vulnerable versions of OpenSSL.
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