An Arbitrary File Upload issue was discovered in 3S-Smart Software Solutions GmbH CODESYS Web Server. The following versions of CODESYS Web Server, part of the CODESYS WebVisu web browser visualization software, are affected: CODESYS Web Server Versions 2.3 and prior. A specially crafted web server request may allow the upload of arbitrary files (with a dangerous type) to the CODESYS Web Server without authorization which may allow remote code execution.