Sql injection union attack determining the number of columns returned by the query | portswigger lab

This lab contains an SQL injection vulnerability in the product category filter. The results from the query are returned in the application's response, so you can use a UNION attack to retrieve data from other tables. The first step of such an attack is to determine the number of columns that are being returned by the query. You will then use this technique in subsequent labs to construct the full attack. To solve the lab, determine the number of columns returned by the query by performing an SQL injection UNION attack that returns an additional row containing null values. portswigger web security sql injection union attacks lab determine number of columns --------------------------------------------------- In this video, CyberWorldSec shows you how to check for sql injecton 🆘🆘NEED HELP?? Join the Discord Server: https://discord.gg/W5vJaaBw FOLLOW ME EVERYWHERE --------------------------------------------------- Instagram : https://www.instagram.com/bug_bunty Telegram group : https://t.me/ethical_hacker_learn Discord: https://discord.gg/W5vJaaBw ------------------------------------------------- Disclaimer : These materials are for educational and research purposes only. These videos teach you cyber secuirty and all the practicals are conducted on a safe to test learning labs provided by PortSwigger's Web Security Academy. PortSwigger's Web Security Academy enables the world to secure the web. Featuring over 190 topics and interactive labs. To know more go to https://portswigger.net/about --------------------------------------------- SUBSCRIBE for more videos! Thanks for watching! Cheers! ---------------------------------------------- portswigger sql injection lab, portswigger sql injection lab solution, portswigger sql injection union attack, portswigger tutorial, portswigger lab walkthrough, portswigger lab solution, portswigger sql, portswigger youtube Determining the number of columns required in an SQL injection UNION attack When performing an SQL injection UNION attack, there are two effective methods to determine how many columns are being returned from the original query. The first method involves injecting a series of ORDER BY clauses and incrementing the specified column index until an error occurs. For example, assuming the injection point is a quoted string within the WHERE clause of the original query, you would submit: ' ORDER BY 1-- ' ORDER BY 2-- ' ORDER BY 3-- etc. This series of payloads modifies the original query to order the results by different columns in the result set. The column in an ORDER BY clause can be specified by its index, so you don't need to know the names of any columns. When the specified column index exceeds the number of actual columns in the result set, the database returns an error, such as: The ORDER BY position number 3 is out of range of the number of items in the select list. The application might actually return the database error in its HTTP response, or it might return a generic error, or simply return no results. Provided you can detect some difference in the application's response, you can infer how many columns are being returned from the query. The second method involves submitting a series of UNION SELECT payloads specifying a different number of null values: ' UNION SELECT NULL-- ' UNION SELECT NULL,NULL-- ' UNION SELECT NULL,NULL,NULL-- etc. If the number of nulls does not match the number of columns, the database returns an error, such as: All queries combined using a UNION, INTERSECT or EXCEPT operator must have an equal number of expressions in their target lists. Again, the application might actually return this error message, or might just return a generic error or no results. When the number of nulls matches the number of columns, the database returns an additional row in the result set, containing null values in each column. The effect on the resulting HTTP response depends on the application's code. If you are lucky, you will see some additional content within the response, such as an extra row on an HTML table. Otherwise, the null values might trigger a different error, such as a NullPointerException. Worst case, the response might be indistinguishable from that which is caused by an incorrect number of nulls, making this method of determining the column count ineffective. LAB SQL injection UNION attack, determining the number of columns returned by the query

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