Classic SQL injection: Attackers capitalize on inadequately sanitized user inputs in this technique. Exploiting the vulnerability, they sneak malicious SQL queries into the application's input fields. Once executed, these rogue queries can manipulate the database, potentially gaining unauthorized access to sensitive data. Preventing classic SQL injection requires meticulous validation and sanitization of user inputs to ensure that no unauthorized code infiltrates the database.
Blind SQL injection: Unlike classic SQL Injection, where attackers receive immediate feedback, blind SQL injection involves manipulating inputs without direct feedback. This technique demands a stealthier approach because attackers must infer the success or failure of their actions based on the application's response time or other subtle cues.
Time-based blind SQL injection: A more refined variant of blind SQL injection, this technique capitalizes on an application's response time. Attackers deliberately induce delays in the application's response to gauge whether the injected query caused any alterations in the database. If the response time changes, attackers can deduce that their malicious code influences the database. Advanced tactics are needed to mitigate this type of injection because it operates within a more covert framework.
Second-order SQL injection: Unlike the immediate damage caused in other types of SQL injection, second-order injection is a delayed-action exploit. Here, attackers introduce malicious code into an application, but the actual harm surfaces when the manipulated data is accessed or used later. This delayed activation makes detection and mitigation more difficult, requiring a vigilant approach to monitor and thwart potential future damage.
Out-of-band SQL injection: This technique showcases attackers' resourcefulness by employing alternative communication channels to extract data from the database. Unlike classic SQL injection, which relies on the application's inherent communication channels, this variant uses external connections to gather the compromised data. Detecting and preventing this type of attack requires monitoring and controlling the application's communication pathways within and beyond its intended boundaries.