I recently went on a PHP course and I was impressed that from minute one the
trainer was hammering home the fact that we need to code defensively.

Specifically escaping user input for these and other nasty sql-injection
techniques hackers use.

It really opened my eyes to how vulnerable a system could be.

Let's be careful out there people ;)

James.


On 25/5/07 00:46, "Aparajita Fishman" <[EMAIL PROTECTED]> wrote:

>> Not sure if it's related, but access to my "logs" directory was
>> another "low" concern which I have now blocked access to.  I
>> noticed the log directory was listed in the URL below, and maybe
>> the two were related.  I have some 3rd party software which
>> analysis my web logs nightly and generates html reports within the
>> logs directory.
> 
> It is up to you to protect the logs directory within an http security
> realm.
> 
> 
>> http://test.superiorbag.com:80/logs?><script>alert('XSS');</script>
>> 
>> The handling of certain HTTP requests that produce "302 Object
>> Moved" responses allows attackers to launch cross-site scripting
>> attacks.  When the server receives an HTTP request for a directory
>> without a trailing slash, it returns a 302 Object Moved error
>> message, redirecting the client to the requested directory, with a
>> forward slash.  Also included in the body of the HTTP response are
>> any GET parameters that were including in the original request.
>> These parameters are not properly sanitized for malicious content
>> before being returned to the client.
> 
> What this is saying is that when a request for the above url is made,
> Active4D redirects to:
> 
> http://test.superiorbag.com:80/logs/?><script>alert('XSS');</script>
> 
> Within the body of the redirect is a link which looks like this if
> you use Safari or IE (but not Mozilla-based browsers):
> 
> <a href="http://test.superiorbag.com:80/logs/?><script>alert('XSS');</
> script>">Click here</a>
> 
> That is what the test was complaining about. However, none of the
> browsers I have tested (even IE6), will actually execute that
> Javascript.
> 
> What EVERYONE should be careful of is not to write values that come
> from user input (or the database) to the page without using
> 'escape' (in Javascript) or 'mac to html' (in Active4D).
> 
> For example, if you allow a user to enter something through the web
> which gets stored in the database, they could enter a bunch of
> javascript code. If you subsequently write the value to the screen,
> the javascript will get executed. In fact my demo suffers from this
> vulnerability. Doh!
> 
> Anyway, the bottom line in this case is that it is a false positive,
> although I will make a change to Active4D so that the query in a
> redirect is url encoded, which effectively sanitizes it.
> 
> Regards,
> 
>     Aparajita
>     www.aparajitaworld.com
> 
>     "If you dare to fail, you are bound to succeed."
>     - Sri Chinmoy   |   www.srichinmoylibrary.com
> 
> 
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