A Stack Buffer Overflow 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 malicious user could overflow the stack buffer by providing overly long strings to functions that handle the XML. Because the function does not verify string size before copying to memory, the attacker may then be able to crash the application or run arbitrary code.