S2-019

Summary

Dynamic Method Invocation disabled by default

Who should read this	All Struts 2 developers and users
Impact of vulnerability	Dynamic method executions
Maximum security rating	Important
Recommendation	Developers should immediately upgrade to Struts 2.3.15.2
Affected Software	Struts 2.0.0 - Struts 2.3.15.1
Reporter	[email protected], HelloWorld security team
CVE Identifier	CVE-2013-4316

Problem

Dynamic Method Invocation is a mechanism known to impose possible security vulnerabilities, but until now it was enabled by default with warning that users should switch it off if possible.

Solution

In Struts 2.3.15.2 the Dynamic Method Invocation is to false by default. Another option is to set struts.enable.DynamicMethodInvocation to false in struts.xml

<constant name="struts.enable.DynamicMethodInvocation" value="false"/>

Backward Compatibility

Disabling Dynamic Method Invocation can break your application if it uses DMI heavily. Nevertheless, please consider to refactor your application to avoid DMI.

It is strongly recommended to upgrade to Struts 2.3.15.2****, which contains the corrected Struts2-Core library.