(PHP 5 >= 5.2.11, PHP 7)
libxml_disable_entity_loader — Disable the ability to load external entities
$disable = true
] )Disable/enable the ability to load external entities.
Returns the previous value.
LIBXML_NONET constant
Using this function you can prevent a vulnerable to Local and Remote File Inclusion attacks.
You'll see it in an example where I load and validate the following string:
<!DOCTYPE scan [<!ENTITY test SYSTEM "php://filter/read=convert.base64-encode/resource=/etc/passwd">]>
<scan>&test;</scan>
One way to prevent that the file in given back is to set this value to 0.
Please take a closer look at the release of symfony 2.0.11
Be mindful that this also disables url loading in simplexml_load_file() and likely other libxml based functions that deal with URLs
This function was reported to be not thread safe. So this might affect php-scripts on the same server.
This also seems to have an impact on <xsl:import /> statements if this is applied when loading XSLT for the XSLTProcessor class.
