Home > Security Bulletins > S2-017 |

Apache Struts 2 Documentation
S2-017
Edit Page Browse Space Add Page Add News

## Summary

A vulnerability introduced by manipulating parameters prefixed with "redirect:"/"redirectAction:" allows for open redirects

Who should read this | All Struts 2 developers and users
Impact of vulnerability | Open redirect
Maximum security rating | Important
Recommendation | Developers should immediately upgrade to Struts 2.3.15.1
Affected Software | Struts 2.0.0 - Struts 2.3.15
Reporter | Takeshi Terada of Mitsui Bussan Secure Directions, Inc.
CVE Identifier | CVE-2013-2248

## Problem

The Struts 2 DefaultActionMapper used to support a method for short-circuit navigation state changes by prefixing parameters with "redirect:" or "redirectAction:", followed by a desired redirect target expression. This mechanism was intended to help with attaching navigational information to buttons within forms.

In Struts 2 before 2.3.15.1 the information following "redirect:" or "redirectAction:" can easily be manipulated to redirect to an arbitrary location.

## Proof of concept

In the Struts Showcase App, open following URLs.

1.     http://host/struts2-showcase/fileupload/upload.action?redirect:http://www.yahoo.com/

2.     http://host/struts2-showcase/modelDriven/modelDriven.action?redirectAction:http://www.google.com/%23

## Solution

DefaultActionMapper was changed to drop the features involved with "redirect:"/"redirectAction:"-prefixed parameters completely - see also S2-016.

Backward Compatibility

After upgrading to Struts >= 2.3.15.1, applications using the "redirect:" / "redirectAction:" functionality will no longer work properly. Please investigate your code to replace such expressions with proper fixed navigation rules.

It is strongly recommended to upgrade to Struts 2.3.15.1, which contains the corrected Struts2-Core library.