If a web server accepts input from the user and passes it to a bash shell, it is vulnerable to command injection. This type of attack occurs when a malicious user sends commands through the input fields, which are then executed by the server's shell, potentially allowing the attacker to execute arbitrary commands, access sensitive data, or take control of the system. Input validation, hash collision, and integer overflow are different vulnerabilities that do not directly pertain to executing shell commands based on user input.
Transaction data is the type of security monitoring data associated with application server logs. Transaction data consists of the messages exchanged during network sessions, which is consistent with the information typically found in application server logs. This includes detailed records of interactions that occur between clients and servers, making it suitable for tracking and analyzing application activity.
The two primary types of cross-site scripting (XSS) attacks are stored and reflected XSS. Stored XSS occurs when malicious scripts are permanently stored on a target server, such as in a database, comment field, or web forum. Reflected XSS happens when a malicious script is reflected off a web server, such as in an error message, search result, or another response that includes some or all of the input sent to the server. Other terms provided, such as 'directed', 'encoded', and 'cascaded' are not recognized types of XSS attacks.