VRT Advisories


VRT Rules 2013-07-11

Sourcefire VRT Rules Update

Date: 2013-07-11

Synopsis:

This release contains an update to the Security over Connectivity base policy and also adds and modifies rules in several categories.

Details:

The Sourcefire VRT has added and modified multiple rules in the browser-ie, browser-plugins, deleted, file-other, malware-cnc and server-webapp rule sets to provide coverage for emerging threats from these technologies.

Policy Changes:

Impact

Under some circumstances, this update may result in a performance change. If you are using the “Security over Connectivity” policy as your base policy, we ask that you review the changes below before re-applying your policies as they may have an effect on the current performance of a sensor.

Policies that will be affected:

Those policies that create or have created a policy based on the Security over Connectivity base layer.

Those policies that have not modified any of the following settings manually.

Changes

The following changes have been made:

HTTP Preprocessor

The HTTP Inspect setting “server_flow_depth” will increase from 0 to 1460

The HTTP Inspect setting “chunk_size” will increase from 10 to 500000

The HTTP Inspect setting “compress_depth” will increase from 1460 to 20000

The HTTP Inspect setting “decompress_depth” will increase from 2920 to 20000

The HTTP Inspect setting “extended_response_inspection” is currently off, this setting will be enabled.

The HTTP Inspect setting “inspect_gzip” is currently off, this setting will be enabled.

Stream Preprocessor

The Stream Preprocessor setting “detect_anomalies” is currently off, this setting will be enabled.

The Stream Preprocessor setting “require_3whs” will increase from 0 to 180

The Stream Preprocessor setting “small_segments” is currently off, this setting will be enabled.

Variables

ORACLE_PORTS will change from “[1521,1526]” to “[1024:]”

GTP_PORTS will increase from “[2123,3386]” to “[2123,2152,3386]”

Rule Pack Summary:

For a complete list of new and modified rules, click here.

Warning:

Sourcefire VRT rule packs often utilize enhancements made to Snort. Operators should upgrade to the latest revision or patch level for Snort to ensure these enhancements are available before using these rules.

About the VRT:

The Sourcefire VRT is a group of leading edge intrusion detection and prevention experts working to proactively discover, assess and respond to the latest trends in hacking activity, intrusion attempts and vulnerabilities. This team is also supported by the vast resources of the open source Snort community, making it the largest group dedicated to advances in the network security industry.

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