Does this if condition can be manipulated using song_genre value?

Question

Here is my code below...

$song_genre = $_GET['song_genre'];
if($song_genre=='bangla'||$song_genre=='hindi'||$song_genre=='english'){ 
    $query = "SELECT `id` FROM `table` WHERE `song_genre` = '$song_genre'";
    mysqli_query($db_connection, $query);
}

I would do, `if(in_array($song_genre, ['bangla','hindi','english'])){...}` but I'm lazy programmer... — ArtisticPhoenix, Nov 09 '17 at 05:57
Not only can it be manipulated, but I can manipulate your entire database with it through SQLInjection, I suggest you do some research on "Prepared statements" And "SQL Injection Attacks" — ArtisticPhoenix, Nov 09 '17 at 06:00
I want to know how this if condition can be true if $_GET['song_genre'] is not equal to bangla or, hindi, or, english. — Rangan Roy, Nov 09 '17 at 06:02

Gordon · Accepted Answer · 2017-11-09T06:15:51.810

0

I want to know how this if condition can be true if $_GET['song_genre'] is not equal to bangla or, hindi, or, english.

Since you are using loose comparison (==) instead of strict comparison (===) the values will type juggle, so a 0 would be true:

var_dump(0 == "bangla"); // bool(true)

But since anything in $_GET will always be a string or an array, there should be no practical way to get the if clause to evaluate to true with anything but the three strings. Nevertheless, use strict comparison.

On a side note: please use prepared statements to guard against sql injection.

edited Nov 09 '17 at 06:15

answered Nov 09 '17 at 06:10

Gordon

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Why zero is equal to any string value?? – Rangan Roy Nov 09 '17 at 08:21
@Rangan because you are using loose comparison and the value will type juggle. Please follow the provided links in my answer to understand this concept if it's unclear to you. – Gordon Nov 09 '17 at 08:37

score 0 · Answer 2 · answered Nov 09 '17 at 06:10

0

if the $_GET['song_genre'] becomes 0 (intvalue) this if statement will be broken .

$song_genre = 0 ; // will break the statement

better check for

if(!empty($song_genre)){
//your code
}

answered Nov 09 '17 at 06:10

User123456

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Does this if condition can be manipulated using song_genre value?

2 Answers2