Apache Struts 2 ParametersInterceptor OGNL Command Injection

Added: 03/26/2012
CVE: CVE-2011-3923
BID: 51628
OSVDB: 78109

Background

Apache Struts is an open-source web application framework for developing Java EE web applications. It uses and extends the Java Servlet API to encourage developers to adopt a model-view-controller (MVC) architecture.

Problem

Struts uses Object-Graph Navigation Language (OGNL) to provide extensive expression evaluation capabilities. Struts 2 versions prior to 2.3.1.2 allow OGNL expressions to be evaluated via parentheses. The ParametersInterceptor class is responsible for passing user-supplied parameters to the application stack. Because ParametersInterceptor does not filter parentheses, it is possible for a user to supply OGNL expressions inside Parentheses, which could result in the execution of arbitrary system commands.

Resolution

Upgrade to Struts 2.3.1.2 or later.

References

<http://struts.apache.org/2.x/docs/s2-008.html&gt;
<https://www.sec-consult.com/files/20120104-0_Apache_Struts2_Multiple_Critical_Vulnerabilities.txt&gt;

Limitations

This exploit has been tested against Apache Software Foundation Struts 2.3.1.1 on Windows Server 2003 SP2 English (DEP OptOut) and Windows Server 2008 SP2 (DEP OptOut).

The executable smbclient must be available on the exploit server, and a valid SMB user with permission to write to the SMB share is required. The smb password is not allowed to contain single quotes (').

Platforms

Windows