sql_injection_-_example_attacks:incorrect_type_handling
SQL Injection - Example attacks - Incorrect type handling
This form of SQL injection occurs when a user-supplied field is not strongly typed or is not checked for type constraints. This could take place when a numeric field is to be used in a SQL statement, but the programmer makes no checks to validate that the user supplied input is numeric. For example:
statement := "SELECT * FROM userinfo WHERE id =" + a_variable + ";"
It is clear from this statement that the author intended a_variable to be a number correlating to the “id” field. However, if it is in fact a string then the end-user may manipulate the statement as they choose, thereby bypassing the need for escape characters. For example, setting a_variable to
1;DROP TABLE users
will drop (delete) the “users” table from the database, since the SQL becomes:
SELECT * FROM userinfo WHERE id=1; DROP TABLE users;
sql_injection_-_example_attacks/incorrect_type_handling.txt · Last modified: 2020/07/15 10:30 by 127.0.0.1