Type Juggling Magic: Why PHP thinks 0 and "password" are the same [Capture The Flag Fundamentals]

When you declare a variable in PHP, you don’t need to define its type - you just declare it. If variables are used as part of a comparison, in order to compare them, PHP needs to guess what those variables represent. After making this guess, PHP will convert the variables to some common data type to then perform the actual comparison.
This can result in unexpected behaviour, which as we’ve seen before and from a security is perspective is almost always a bad idea.
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[@247CTF]

👍 Liking this video will increase your ability to solve CTF challenges by 0e100000% 👍

[@RhyanGarrison]

Always use that === for strict comparison with PHP!

[@247CTF]

Equality vs identity 👌

[@bourbon3406]

Didn't know 247CTF had a channel! This is cool. Subbed

[@andkiek]

Love this channel!

[@zerosploit]

More please! I love the videos

[@247CTF]

Ok.. Will release a new video today since you asked so nicely 🤘

[@zerosploit]

@@247CTF i cant wait

[@louisbarasa5741]

Neat stuff🔥🔥🔥.

[@247CTF]

Thanks 🔥

[@ctfs09]

I guess you need to release new version of this video

[@247CTF]

You think everyone has updated?

[@ctfs09]

@@247CTF sooner or later they will and they have to

[@nameless3704]

Great Video! What about that? if ($user_input == substr(md5($user_input), 0, 24)

[@247CTF]

It shouldn't make any difference right? The leading bytes enable this 'attack', not the trailing bytes.

[@nameless3704]

​@@247CTF yeah, you're right. I've figured it out this challenge today. I've wrote a python script that is able to brute force a string that begin with '0e' and if also his md5 begin '0e' it return the strings that satisfies the condition. The string in question is: 0e1111111223334448888 --> md5 hash: 0e876388751226915717729537293291 Thank you so much for your reply.

[@247CTF]

Nice work!