Description
Apache Struts 2 before 2.2.3.1 evaluates a string as an OGNL expression during the handling of a conversion error, which allows remote attackers to modify run-time data values, and consequently execute arbitrary code, via invalid input to a field.
Remediation
References
http://jvn.jp/en/jp/JVN79099262/index.html
http://jvndb.jvn.jp/jvndb/JVNDB-2012-000012
http://struts.apache.org/2.3.1.2/docs/s2-007.html
https://issues.apache.org/jira/browse/WW-3668