SQL Injection kese kaam krta he🤔

 SQL Injection ek technique hai jo attacker ko ek database mein unauthorized access ya manipulation karne ka moka deti hai. Yeh tab hota hai jab koi application user ke input ko SQL query mein directly use karti hai bina us input ko sanitize kiye. Aise mein, agar attacker apne input mein malicious SQL code inject kar de, toh woh database ke data ko access, modify, delete ya manipulate kar sakta hai.

Kaise Kaam Karta Hai

1. Vulnerable Input Field: Jab kisi website mein koi input field ho (jaise username ya password), aur woh input directly SQL query mein bina sanitize kiye use ho, toh woh vulnerable hoti hai.

2. SQL Query Manipulation: Attacker usually input ke sath SQL syntax add karta hai, jo existing query ko manipulate karti hai. Example:

   sql
   
   SELECT * FROM users WHERE username = 'user' AND password = 'password';
   

   Agar attacker username field mein user' OR '1'='1 daal de, toh query kuch aise ban jayegi:

   sql
   
   SELECT * FROM users WHERE username = 'user' OR '1'='1' AND password = 'password';
   

   Yeh query "OR '1'='1'" ki wajah se hamesha true return karti hai, jo database ko unauthorized access dene ka moka deti hai.

3. Database Commands: Advanced level par, attacker UNION, DROP TABLE, ya -- jaise commands bhi use kar sakta hai jo database ko manipulate ya damage kar sakti hain.

SQL Injection Se Bachav Kaise Kare

1. Parameterized Queries (Prepared Statements): Yeh queries input ko as a data treat karti hain, code ke taur par nahi. Jaise:

   
   cursor.execute("SELECT * FROM users WHERE username = ? AND password = ?", (username, password))
   

2. Input Sanitization: Har user input ko sanitize kare, special characters ko escape karein aur input validate karein.

3. Error Messages ko Limit Karna: SQL errors ko generic banayein taake attacker ko zyada details na mil sakein.

4. Database Permissions ko Limit Karna: Database user permissions ko restrict karein taake agar SQL injection ho bhi jaaye, toh damage minimum ho.

SQL Injection ko effectively roknay ke liye yeh best practices follow karna zaroori hai.