Worst security hole you've seen? [closed]

Solution 1:

From early days of online stores:

Getting a 90% discount by entering .1 in the quantity field of the shopping cart. The software properly calculated the total cost as .1 * cost, and the human packing the order simply glossed over the odd "." in front of the quantity to pack :)

Solution 2:

The least forgivable security hole, and unfortunately a very common and easy to find one at that, is Google hacking. Case in point:

http://www.google.com/search?q=inurl%3Aselect+inurl%3A%2520+inurl%3Afrom+inurl%3Awhere

It's amazing how many pages on the Internet, government sites in particular, pass an SQL query through the query string. It's the worst form of SQL injection, and it takes no effort at all to find vulnerable sites.

With minor tweaks, I've been able to find unprotected installations of phpMyAdmin, unprotected installations of MySQL, query strings containing usernames and passwords, etc.

Solution 3:

Social Engineering:

<Cthon98> hey, if you type in your pw, it will show as stars
<Cthon98> ********* see!
<AzureDiamond> hunter2
<AzureDiamond> doesnt look like stars to me
<Cthon98> <AzureDiamond> *******
<Cthon98> thats what I see
<AzureDiamond> oh, really?
<Cthon98> Absolutely
<AzureDiamond> you can go hunter2 my hunter2-ing hunter2
<AzureDiamond> haha, does that look funny to you?
<Cthon98> lol, yes. See, when YOU type hunter2, it shows to us as *******
<AzureDiamond> thats neat, I didnt know IRC did that
<Cthon98> yep, no matter how many times you type hunter2, it will show to us as *******
<AzureDiamond> awesome!
<AzureDiamond> wait, how do you know my pw?
<Cthon98> er, I just copy pasted YOUR ******'s and it appears to YOU as hunter2 cause its your pw
<AzureDiamond> oh, ok.

From bash.org