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Bug #73354 URL filter validator broken
Submitted: 2016-10-19 20:07 UTC Modified: 2016-10-20 09:45 UTC
Votes:1
Avg. Score:3.0 ± 0.0
Reproduced:1 of 1 (100.0%)
Same Version:1 (100.0%)
Same OS:1 (100.0%)
From: mehulmpt at gmail dot com Assigned:
Status: Verified Package: Filter related
PHP Version: Irrelevant OS: All
Private report: No CVE-ID: None
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 [2016-10-19 20:07 UTC] mehulmpt at gmail dot com
Description:
------------
filter validate URL is broken for non HTTP(s) protocols as it allows a variety of URLs to pass through though they are not valid URLs (possible XSS attacks if URL is displayed after validating)

Test script:
---------------
<?php

echo filter_var("ftp://oscarotero.com;<script>alert()</script>", FILTER_VALIDATE_URL); // outputs JS alert box.

?>




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 [2016-10-20 01:11 UTC] yohgaki@php.net
-Status: Open +Status: Verified
 [2016-10-20 09:45 UTC] cmb@php.net
Indeed, there is an issue in php_filter_url()[1], namely that
PUNCTUATION and NATIONAL are not allowed in URLs according to RFC
1738. While these are listed in the BNF, they are never used.

However, according to the documentation FILTER_VALIDATE_URL
conforms to RFC 2396, which differs from RFC 1738.

[1] <http://lxr.php.net/source/xref/PHP-MASTER/ext/filter/sanitizing_filters.c#php_filter_url>
 
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