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TextFileBB 1.0.16 Multiple XSS
From: r0xes.ratm () gmail com
Date: 29 Apr 2006 19:15:49 -0000
TextFileBB is a flat-file based bulletin board system written in PHP.
There are 3 different XSS vulnerabilities in this software at the moment, which I found about half an hour ago =D
Anyway, the XSS lies in these tags:
Firstly, we'll explain [color].
[code][.color=#00'">0FFF] """xss [/color][/code]
Would give us:
[code]<font >0fff="" color="#000000"> """xss </font>[/code]
Therefore we can see that we actually are breaking the tag and that our last part (0FFF) is stripped (funnily enough I
found this by typo.)
So, we need to do:
As this would give us:
[code]<font onmouseover="alert(/xss/)" x="" color="#000000">h0n0</font>[/code]
We use the #00F to start the color (so that it IS parsed [attempted to be] by the parser), and break out of that with
our quote - it'll be replaced with a space. The color will be left as #000000. I added the x="" attribute because I
noticed it wouldn't render in IE for some wierd reason.
This is basically the same as [color], but tad different.
[code][.size=7" OnMouseOver="alert(/xss/)]Clicky Here [/size][/code]
We break out of the size with the first quote, and then use our MouseOver - we do not close the MouseOver ourselves
because the parser will enclose everything in "".
Turns into: (something like)
[code]<font size="7" onMouseOver="alert(/xss/)">Clicky Here</font>[/code]
I don't think the parser cares whether or not you include the http://, but I added it just as an example.
Same as with [size], we break out of the href and then do not add a " to the end because the parser will do it for us.
TextFileBB stores user information in cookies, so you could steal the administrator's cookies and take over the board.
Credits: me =D
Shouts: digi7al64 - PrOtOn - Lockdown - WhiteAcid
- TextFileBB 1.0.16 Multiple XSS r0xes . ratm (Apr 30)