Broken Access Control Vulnerability in Apache Struts2
Who should read this
All Struts 2 developers and users
Impact of vulnerability
Permissions, Privileges, and Access Controls
Maximum security rating
Developers should immediately upgrade to Struts 18.104.22.168
Struts 2.0.0 - Struts 22.214.171.124
Zhu Gang, Zhang Jin, Huawei PSIRT
The Struts 2 action mapping mechanism supports the special parameter prefix action: which is intended to help with attaching navigational information to buttons within forms.
In Struts 2 before 126.96.36.199, under certain conditions this can be used to bypass security constraints. More details will available later on when the patch will be widely adopted.
In Struts 188.8.131.52 the action mapping mechanism was changed to avoid circumventing security constraints. Two additional constants were introduced to steer behaviour of DefaultActionMapper:
- struts.mapper.action.prefix.enabled - when set to false support for "action:" prefix is disabled, set to false by default
- struts.mapper.action.prefix.crossNamespaces - when set to false, actions defined with "action:" prefix must be in the same namespace as current action
After upgrading to Struts 184.108.40.206, applications using the "action:" will stop working. You can use above constants to steer that behaviour.
It is strongly recommended to upgrade to Struts 220.127.116.11, which contains the corrected Struts2-Core library.