2023-06-22 11:25:00 +02:00

55 lines
1.2 KiB
Plaintext

== How to fix it in Core PHP
=== Code examples
include::../../common/fix/code-rationale.adoc[]
==== Noncompliant code example
[source,php,diff-id=1,diff-type=noncompliant]
----
$xml = file_get_contents('xxe.xml');
$doc = simplexml_load_string($xml, 'SimpleXMLElement', LIBXML_NOENT); // Noncompliant
----
[source,php,diff-id=2,diff-type=noncompliant]
----
$doc = new DOMDocument();
$doc->load('xxe.xml', LIBXML_NOENT); // Noncompliant
----
[source,php,diff-id=3,diff-type=noncompliant]
----
$reader = new XMLReader();
$reader->open('xxe.xml');
$reader->setParserProperty(XMLReader::SUBST_ENTITIES, true); // Noncompliant
----
==== Compliant solution
External entity substitution is disabled by default in `simplexml_load_string()` and `DOMDocument::open()`.
[source,php,diff-id=1,diff-type=compliant]
----
$xml = file_get_contents('xxe.xml');
$doc = simplexml_load_string($xml, 'SimpleXMLElement');
----
[source,php,diff-id=2,diff-type=compliant]
----
$doc = new DOMDocument();
$doc->load('xxe.xml');
----
[source,php,diff-id=3,diff-type=compliant]
----
$reader = new XMLReader();
$reader->open('xxe.xml');
$reader->setParserProperty(XMLReader::SUBST_ENTITIES, false);
----
=== How does this work?
include::../../common/fix/xxe.adoc[]