Re: solutions to disadvantages when register_globals is off

For experienced PHP developers having register_globals on should not be a security issue. Injecting arbitrary variables into your symbol table is only a problem if you arbitrarily use such variables without initializing or checking them for validity. I think the main point of concern here is that register_globals makes life very easy on inexperienced developers and these are the same people most likely to do something silly like: <? include $file; ... ?> Note that doing: <? include $HTTP_POST_VARS['file']; ... ?> really isn't any safer. People won't be able to put file=/etc/passwd right in the URL, but they can still trivially fake up a form post and inject whatever value for 'file' into the POST data. It all boils down to verifying any and all user-supplied data. -Rasmus On Sun, 21 Jan 2001, Dale Robinson wrote: > Everyone seems to recommend turning off register_globals, but accessing them > through $HTTP_POST_VARS["var_name"], gets tedious. > > I haven't found a better solution (not to say there isn't one) than this > small snippet. > > The idea is to turn off "register_globals", as I believe is heavily > recommended by the PHP team, and declare what variables you are expecting on > a per script basis. > Magic-quotes would also be off. Hopefully this makes all external variables > safe. > > I was hoping some experienced users would cast their eye over this and > suggest any improvements, and comment if it is worth doing at all > > define("ALLOWABLE_HTML_TAGS", "<B><H1>"); > > function use_ext_var($var_name, $var_location) > { > global $$var_name, $$var_location; > > $$var_name = ${$var_location}[$var_name]; > $$var_name = stripslashes($$var_name); > $$var_name = strip_tags($$var_name, ALLOWABLE_HTML_TAGS); > > } > > use_ext_var("sample_var", "HTTP_GET_VARS"); > print $sample_var; > > How are other people handling this, or are most of you 'lazy' and just use > globals :) > > Regards > > D Robinson > > > > -- > PHP General Mailing List (http://www.php.net/) > To unsubscribe, e-mail: php-general-unsubscribe@lists.php.net > For additional commands, e-mail: php-general-help@lists.php.net > To contact the list administrators, e-mail: php-list-admin@lists.php.net >