Summary
Cross site scripting (XSS) vulnerability on <s:url> and <s:a> tags
Who should read this |
All Struts 2 developers |
---|---|
Impact of vulnerability |
Injection of malicious client side code |
Maximum security rating |
Important |
Recommendation |
Developers using Struts 2 tags should immediately upgrade to Struts 2.2.3 |
Affected Software |
Struts 2.0.0 - Struts 2.2.1.1 |
Original JIRA Tickets |
Problem
For both the <s:url> and the <s:a> tag, it is possible to inject parameter values that do not get escaped properly when the tag's resulting URLs are constructed and rendered. The following scenarios are known:
- A parameter value included in the construction of a <s:a> result can inject an unescaped double quote, thus being able to inject code in the resulting HTML by escaping the rendered
href
attribute. - Both the <s:url> and the <s:a> tag fail to escape <script> tags when
includeParams
is set to any other value than "none", which can be exploited by calling the containing JSP/action with GET parameters such ashttp://localhost/foo/bar.action?<script>alert(1)</script>test=hello
Solution
As of Struts 2.0.11.1
- Double quotes do get escaped for parameter values used to constuct the output of a <s:a> tag
- <script> tokens do get recursively escaped for parameter values used to contruct the output of <s:a> and <s:url> tags
You can obtain Struts 2.0.11.1 as a drop in replacement for Struts 2.0.11 to get the fixed Struts 2 core library.