Quote:The Apache Software Foundation warned in an advisory that the latest version of the Commons FileUpload library is susceptible to a two-year-old remote code execution flaw. Users of the vulnerable library must update their projects manually.

The critical bug in Commons FileUpload library is a known vulnerability (CVE-2016-1000031) that enables remote code execution in the open-source framework, which facilitates developing web applications in the Java programming language. Essentially a Java Object exists in the Apache Commons FileUpload library that can be manipulated so that when it is deserialized, it can write or copy files to disk in arbitrary locations.

“A remote attacker could exploit this vulnerability to take control of an affected system,” according to the Monday advisory. “Your project is affected if it uses the built-in file upload mechanism of Struts 2, which defaults to the use of commons-fileupload. The updated commons-fileupload library is a drop-in replacement for the vulnerable version. Deployed applications can be hardened by replacing the commons-fileupload jar file in WEB-INF/lib with the fixed jar.”