Sql+injection+challenge+5+security+shepherd+new -
The key insight is that the escaping function is programmed to replace single quote with a backslash followed by a quote ( \' ). This includes single quotes that are already preceded by a backslash. Consequently, when the function encounters a backslash followed by a quote ( \' ), it transforms it into \\' .
If you enter 1 and 1=1 , the server might respond with a 200 OK. But if you enter a more complex payload like 1 UNION SELECT username FROM users , the filter kicks in. How do we bypass space filtering?
Master Guide: Cracking the SQL Injection Challenge 5 on OWASP Security Shepherd
MySQL (and many underlying DBMS platforms used in Shepherd) is case-insensitive for keywords. sql+injection+challenge+5+security+shepherd+new
Crucially, the application employs an escaping function that (and only the single quote). It does not escape double quotes ( " ).
-- VULNERABLE "SELECT * FROM users WHERE username = '" + userVar + "';" -- SECURE "SELECT * FROM users WHERE username = ?;" Use code with caution.
Commonly known as the "SQL Injection Escaping Challenge," this level simulates a real-world scenario where an application attempts to sanitize user input by manually adding backslashes to escape characters like single quotes ( ' ). Rather than securing the application, this implementation introduces a flaw that allows structural manipulation of the backend query. The key insight is that the escaping function
To securely fix this flaw, completely avoid character replacement schemes. Use native . This design binds the input explicitly as a data variable, ensuring backslashes or quotation marks can never re-write the SQL query logic. Vulnerable Code Blueprint (Anti-Pattern)
Reconnaissance
If a user attempts a classic injection payload like ' OR 1=1; -- , the escaping function intercepts the single quote. The input becomes \' OR 1=1; -- . The backend query would then look like: If you enter 1 and 1=1 , the
If you inject: \' OR 1=1 -- The application might escape the quote, turning it into: \\' OR 1=1 --
The server uses a vulnerable SQL query to check if a coupon code exists. The backend code for this challenge (found on GitHub ) reveals that user input is directly concatenated into a SELECT statement:
Another widely successful payload is \'or"1"="1"; -- , which cleverly combines the escaped single quote injection technique with double-quote logic to achieve the same result.
