Re: Echoing input w/o sanatizing - what is the danger

I know how you can use cross site scripting if you can steal cookies and do bad stuff with JS. My question now though is if I have a form, and I post to myself and just echo the value of that post, is that bad? Nobody else would see the result of my post so no malicous JS could ever do anything. I'm not doing any database calls, just storing what they typed in either an array or a variable and echoing it. Simple as that. Is that insecure? - Dan ""Daniel Brown"" <parasane@gmail.com> wrote in message news:ab5568160708071520n20ee9f85l81b294b73c467ec@mail.gmail.com...

I'm just forwarding this as a courtesy to the list, because Anthony accidentally just sent it to me, as opposed to "Reply-All'ing" the list. If you want more information on this subject you should search Google for "Cross Site Scripting" and "XSS". Of particular interest is this site: http://ha.ckers.org/xss.html which demonstrates various ways XSS can be exploited. Also if you aren't just echo'ing the data, but taking unsanitized data and making database calls with it, you will want to look for MySQL injection techniques. Cheers, distatica. On 8/7/07, Daniel Brown <parasane@gmail.com> wrote:

On 8/7/07, Dan <frozendice@gmail.com> wrote:

I've always heard it is bad if you let a user type some input, then show it back to them w/o sanatizing the code. Eg. I have a form, where the user types something, they hit submit and it submits to itself then prints back to the user something like, account created with password: whatever they typed. Why and how do you sanatize what they typed before echoing it back to them? I figured it was something like they could type in PHP commands but I tried typeing phpinfo(); into the box and submitting. All that happened is that it echoed phpinfo(); Can someone explain this? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php

    It's actually not so much for echo'ing as it is for processing the

data in another manner that makes it dangerous not to do some sanitizing and checking.... such as database manipulation. -- Daniel P. Brown [office] (570-) 587-7080 Ext. 272 [mobile] (570-) 766-8107 Hey, PHP-General list.... to give something back to everyone, you guys can have 50% off every month on hosting plans of $10/mo. or more (list price) at http://www.pilotpig.net/. Use the coupon code phpgeneralaug07 -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php

-- --------------------------------- Anthony Hiscox Video Watch Group Public Site Currently Under Development Group Members Site Fully Operational --------------------------------- -- Daniel P. Brown [office] (570-) 587-7080 Ext. 272 [mobile] (570-) 766-8107 Hey, PHP-General list.... to give something back to everyone, you guys can have 50% off every month on hosting plans of $10/mo. or more (list price) at http://www.pilotpig.net/. Use the coupon code phpgeneralaug07