[Full-disclosure] Critical PHP bug - act ASAP if you are running web with sensitive data

Jasper Bryant-Greene jasper at album.co.nz
Mon Apr 3 23:15:13 BST 2006


Jasper Bryant-Greene wrote:
> Moriyoshi Koizumi wrote:
>> Jasper Bryant-Greene wrote:
>>
>>> I very much doubt there are many applications at all containing code 
>>> like this. It is illogical to be decoding html entities from user 
>>> input. Therefore I would not call this a "very serious problem" and 
>>> certainly not a critical bug.
>>
>> Not really. While this is not part of the HTML / HTTP standards, major 
>> browsers
>> around try to send such characters in the user input as HTML entities 
>> that cannot
>> all be represented in the encoding of the originating HTML page, it's 
>> quite probable
>> the function is used to filter the query strings.
> 
> Indeed, it probably is, but hopefully the results of that are not then 
> echoed out to the browser without running htmlspecialchars() etc on 
> them... If they are (which is the root of this "security problem") then 
> that is the fault of the idiot who wrote the code, not PHP. You can only 
> protect users from their own stupidity to a certain degree...
> 

OK, ignore that, forgot what we were talking about for a while there :)

htmlspecialchars() should still be run on the output, otherwise you have 
another security hole, but of course that won't protect against sending 
memory contents back to the user...

-- 
Jasper Bryant-Greene
General Manager
Album Limited

http://www.album.co.nz/     0800 4 ALBUM
jasper at album.co.nz          021 708 334




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