This detection rule targets CVE-2023-50164, a critical path traversal vulnerability found in the Apache Struts 2 file upload functionality. It identifies a malicious sequence of events indicating successful exploitation, where an attacker sends a multipart/form-data POST request containing 'WebKitFormBoundary' to a Struts upload endpoint, followed closely by the creation of a JSP web shell file via a Java process. This activity suggests unauthorized remote code execution capability after file upload is achieved. The rule cross-correlates network traffic data and file creation events on Linux servers to determine if exploitation has occurred. Given the specific nature of the detection, false positives are rare, as legitimate applications typically do not generate concurrent uploads and JSP file creation under this context.