| Home > Security Bulletins > S2-024 |
excludeParams overrides those defined in DefaultExcludedPatternsCheckerWho should read this | All Struts 2 developers and users |
|---|---|
Impact of vulnerability | If default settings are used, the attacker can compromise internal state of an application |
Maximum security rating | Medium |
Recommendation | Developers should immediately upgrade to Struts 2.3.20.1 or introduce the below change in framework's settings |
Affected Software | Struts 2.3.20 |
Reporter | Jasper Rosenberg at Cargurus |
CVE Identifier | CVE-2015-1831 |
Wrong default exclude patterns were introduced in version 2.3.20 of Struts, if default settings are used, the attacker can compromise internal application's state.
In Struts 2.3.20.1 a better set of exlude patterns was defined.
No backward compatibility problems are expected.
If you cannot migrate to the latest version it's highly recommended to re-define defaultStack from struts-default.xml to this one below (or any other which is used in your application and drop excludeParams parameter):
<interceptor-stack name="myDefaultStack">
<interceptor-ref name="exception"/>
<interceptor-ref name="alias"/>
<interceptor-ref name="servletConfig"/>
<interceptor-ref name="i18n"/>
<interceptor-ref name="prepare"/>
<interceptor-ref name="chain"/>
<interceptor-ref name="scopedModelDriven"/>
<interceptor-ref name="modelDriven"/>
<interceptor-ref name="fileUpload"/>
<interceptor-ref name="checkbox"/>
<interceptor-ref name="datetime"/>
<interceptor-ref name="multiselect"/>
<interceptor-ref name="staticParams"/>
<interceptor-ref name="actionMappingParams"/>
<interceptor-ref name="params"/>
<interceptor-ref name="conversionError"/>
<interceptor-ref name="validation">
<param name="excludeMethods">input,back,cancel,browse</param>
</interceptor-ref>
<interceptor-ref name="workflow">
<param name="excludeMethods">input,back,cancel,browse</param>
</interceptor-ref>
<interceptor-ref name="debugging"/>
<interceptor-ref name="deprecation"/>
</interceptor-stack>
and define the following constant in struts.xml
<constant name="struts.additional.excludedPatterns" value="^(action|method):.*"/>