Summary
Use of a JRE with broken URLDecoder implementation may lead to XSS vulnerability in Struts 2 based web applications.Who should read this | All Struts 2 developers and users |
|---|---|
Impact of vulnerability | Affects of a cross-site scripting vulnerability. |
Maximum security rating | Important |
Recommendation | Upgrade runtime JRE to a recent major version, preferably 1.8. Alternatively upgrade to Struts 2.3.28 |
Affected Software | Struts 2.0.0 - Struts Struts 2.3.24.1 |
Reporter | WhiteHat Security (whitehatsec.com) |
CVE Identifier | CVE-2016-4003 |
Problem
When using a single byte page encoding such as ISO-8895-1, an attacker might submit a non-spec URL-encoded parameter value including multi-byte characters.
Struts 2 used the standard JRE URLDecoder to decode parameter values. Especially JRE 1.5's URLDecoder implementation seems to be broken to the point that this non-spec encoding isn't rejected / filtered. In later JREs the issue was fixed, best known solution is found in JRE 1.8.
Solution
Upgrade runtime JRE/JDK, preferably to the most recent 1.8 version.
Alternatively upgrade to Struts 2.3.28, which includes and uses a safe URLDecoder implementation from Apache Tomcat
Backward compatibility
No issues expected when upgrading to Struts 2.3.28
Workaround
Use UTF-8 for page and parameter encoding.
Further Reference
WW-4507 - Getting issue details... STATUS