Tag Archives: insert update delete statements sqli

SQL Injection in Insert, Update and Delete Statements

102
Filed under SQL Injection
Tagged as , , ,

Introduction

Most of the time when we talk about SQL injection we extract data by using the union keyword, error based, blind boolean and time based injection methods. All this comes under a place where the application is performing a SELECT statement on the back-end database. How to inject into places where the application is performing an INSERT, UPDATE, DELETE statement? For example, INSERT statements are used in applications when it wants to store IP addresses, user agent strings, referrer URLs and other data within the database. While manipulating with user accounts when creating a new password, changing names, deleting accounts these statements are used. Not only just user input if we can fuzz around into whatever the application is taking as input and if they aren’t properly sanitized to filter we can go ahead and inject (Assuming that there are no WAFs or any blacklists). This paper is based on the MySQL error response. In the web application mysql_error() should be echoed back to us.

Lab Setup

Let’s create a database first by the name `newdb` and create one sample table to practice our injections. Stick to your localhost. Don’t go ahead and test against live websites without prior permission. I take no responsibility for any damage you cause.

Create database newdb;
use newdb
CREATE TABLE users
(
id int(3) NOT NULL AUTO_INCREMENT,
username varchar(20) NOT NULL,
password varchar(20) NOT NULL,
PRIMARY KEY (id)
);

Read More »