News Feed
Sections




News Archive
Looking for more information on how to do PHP the right way? Check out PHP: The Right Way

PHP Security Blog:
Holes in most preg_match() filters
April 04, 2007 @ 07:15:50

On the PHP Security Log today, Stefan Esser points out some holes in most of the filters using preg_match that he's seen in examples and the like all around the web. Some of these things could cause issues that could breach the security of your application.

During the last week I was performing some audits and like so often it contained preg_match() filters that were not correct. Most PHP developers use ^ and $ within their regular expressions without actually reading the documentation about what they really achieve.

However the problem is, that the author of such a regular expression did not correctly read the documentation and mistakes the $ character for the definitive end of the subject.

According to Stefan, the actual documentation for the $ character in a regular expression isn't quite used that way. It does mean "the end" of the match but it can also match against a newline as well. His suggestions? Use the /D modifier on the end of the expression to match the real "the end" and not how it might match otherwise.

0 comments voice your opinion now!
security pregmatch filter match endofline clean security pregmatch filter match endofline clean


blog comments powered by Disqus

Similar Posts

php|architect: Modsecurity: Why it matters to PHP

Ilia Alshanetsky\'s Blog: php|tek Slides Posted

Secunia.com: PHP Integer Overflow Vulnerability and Security Bypass

Secunia.com: Debian Updates for PHP4 and PHP5 Users

SitePoint PHP Blog: PHP ZH Round One


Community Events

Don't see your event here?
Let us know!


release wordpress development series api podcast interview unittest opinion laravel5 framework library introduction threedevsandamaybe extension voicesoftheelephpant language feature community laravel

All content copyright, 2015 PHPDeveloper.org :: info@phpdeveloper.org - Powered by the Solar PHP Framework