File size: 10,828 Bytes
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index 58c8111..79a350a 100644
--- a/src/Sanitizer.php
+++ b/src/Sanitizer.php
@@ -214,13 +214,10 @@ public function sanitize($dirty)
$this->elementReferenceResolver->collect();
$elementsToRemove = $this->elementReferenceResolver->getElementsToRemove();
- // Grab all the elements
- $allElements = $this->xmlDocument->getElementsByTagName("*");
-
// remove doctype after node elements have been analyzed
$this->removeDoctype();
// Start the cleaning proccess
- $this->startClean($allElements, $elementsToRemove);
+ $this->startClean($this->xmlDocument->childNodes, $elementsToRemove);
// Save cleaned XML to a variable
if ($this->removeXMLTag) {
@@ -316,33 +313,63 @@ protected function startClean(\DOMNodeList $elements, array $elementsToRemove)
continue;
}
- // If the tag isn't in the whitelist, remove it and continue with next iteration
- if (!in_array(strtolower($currentElement->tagName), $this->allowedTags)) {
- $currentElement->parentNode->removeChild($currentElement);
- $this->xmlIssues[] = array(
- 'message' => 'Suspicious tag \'' . $currentElement->tagName . '\'',
- 'line' => $currentElement->getLineNo(),
- );
- continue;
- }
-
- $this->cleanHrefs($currentElement);
-
- $this->cleanXlinkHrefs($currentElement);
-
- $this->cleanAttributesOnWhitelist($currentElement);
-
- if (strtolower($currentElement->tagName) === 'use') {
- if ($this->isUseTagDirty($currentElement)
- || $this->isUseTagExceedingThreshold($currentElement)
- ) {
+ if ($currentElement instanceof \DOMElement) {
+ // If the tag isn't in the whitelist, remove it and continue with next iteration
+ if (!in_array(strtolower($currentElement->tagName), $this->allowedTags)) {
$currentElement->parentNode->removeChild($currentElement);
$this->xmlIssues[] = array(
- 'message' => 'Suspicious \'' . $currentElement->tagName . '\'',
+ 'message' => 'Suspicious tag \'' . $currentElement->tagName . '\'',
'line' => $currentElement->getLineNo(),
);
continue;
}
+
+ $this->cleanHrefs( $currentElement );
+
+ $this->cleanXlinkHrefs( $currentElement );
+
+ $this->cleanAttributesOnWhitelist($currentElement);
+
+ if (strtolower($currentElement->tagName) === 'use') {
+ if ($this->isUseTagDirty($currentElement)
+ || $this->isUseTagExceedingThreshold($currentElement)
+ ) {
+ $currentElement->parentNode->removeChild($currentElement);
+ $this->xmlIssues[] = array(
+ 'message' => 'Suspicious \'' . $currentElement->tagName . '\'',
+ 'line' => $currentElement->getLineNo(),
+ );
+ continue;
+ }
+ }
+
+ // Strip out font elements that will break out of foreign content.
+ if (strtolower($currentElement->tagName) === 'font') {
+ $breaksOutOfForeignContent = false;
+ for ($x = $currentElement->attributes->length - 1; $x >= 0; $x--) {
+ // get attribute name
+ $attrName = $currentElement->attributes->item( $x )->name;
+
+ if (in_array($attrName, ['face', 'color', 'size'])) {
+ $breaksOutOfForeignContent = true;
+ }
+ }
+
+ if ($breaksOutOfForeignContent) {
+ $currentElement->parentNode->removeChild($currentElement);
+ $this->xmlIssues[] = array(
+ 'message' => 'Suspicious tag \'' . $currentElement->tagName . '\'',
+ 'line' => $currentElement->getLineNo(),
+ );
+ continue;
+ }
+ }
+ }
+
+ $this->cleanUnsafeNodes($currentElement);
+
+ if ($currentElement->hasChildNodes()) {
+ $this->startClean($currentElement->childNodes, $elementsToRemove);
}
}
}
@@ -627,4 +654,50 @@ public function setUseNestingLimit($limit)
{
$this->useNestingLimit = (int) $limit;
}
+
+ /**
+ * Determines whether a node is safe or not.
+ *
+ * @param \DOMNode $node
+ * @return bool
+ */
+ protected function isNodeSafe(\DOMNode $node) {
+ $safeNodes = [
+ '#text',
+ ];
+
+ if (!in_array($node->nodeName, $safeNodes, true)) {
+ return false;
+ }
+
+ return true;
+ }
+
+ /**
+ * Remove nodes that are either invalid or malformed.
+ *
+ * @param \DOMNode $currentElement The current element.
+ */
+ protected function cleanUnsafeNodes(\DOMNode $currentElement) {
+ // If the element doesn't have a tagname, remove it and continue with next iteration
+ if (!property_exists($currentElement, 'tagName')) {
+ if (!$this->isNodeSafe($currentElement)) {
+ $currentElement->parentNode->removeChild($currentElement);
+ $this->xmlIssues[] = array(
+ 'message' => 'Suspicious node \'' . $currentElement->nodeName . '\'',
+ 'line' => $currentElement->getLineNo(),
+ );
+
+ return;
+ }
+ }
+
+ if ( $currentElement->childNodes && $currentElement->childNodes->length > 0 ) {
+ for ($j = $currentElement->childNodes->length - 1; $j >= 0; $j--) {
+ /** @var \DOMElement $childElement */
+ $childElement = $currentElement->childNodes->item($j);
+ $this->cleanUnsafeNodes($childElement);
+ }
+ }
+ }
}
diff --git a/src/data/AllowedTags.php b/src/data/AllowedTags.php
index 5b0f3de..e8d1795 100644
--- a/src/data/AllowedTags.php
+++ b/src/data/AllowedTags.php
@@ -29,56 +29,35 @@ public static function getTags()
'article',
'aside',
'audio',
- 'b',
'bdi',
'bdo',
- 'big',
'blink',
- 'blockquote',
- 'body',
- 'br',
'button',
'canvas',
'caption',
- 'center',
'cite',
- 'code',
'col',
'colgroup',
'content',
'data',
'datalist',
- 'dd',
'decorator',
'del',
'details',
'dfn',
'dir',
'div',
- 'dl',
- 'dt',
'element',
- 'em',
'fieldset',
'figcaption',
'figure',
'font',
'footer',
'form',
- 'h1',
- 'h2',
- 'h3',
- 'h4',
- 'h5',
- 'h6',
- 'head',
'header',
'hgroup',
- 'hr',
'html',
- 'i',
'image',
- 'img',
'input',
'ins',
'kbd',
@@ -89,52 +68,27 @@ public static function getTags()
'map',
'mark',
'marquee',
- 'menu',
- 'menuitem',
'meter',
'nav',
- 'nobr',
- 'ol',
'optgroup',
'option',
'output',
- 'p',
- 'pre',
'progress',
'q',
'rp',
'rt',
- 'ruby',
- 's',
'samp',
'section',
'select',
'shadow',
- 'small',
'source',
'spacer',
- 'span',
- 'strike',
- 'strong',
'style',
- 'sub',
'summary',
- 'sup',
- 'table',
- 'tbody',
- 'td',
'template',
'textarea',
- 'tfoot',
- 'th',
- 'thead',
'time',
- 'tr',
'track',
- 'tt',
- 'u',
- 'ul',
- 'var',
'video',
'wbr',
diff --git a/tests/SanitizerTest.php b/tests/SanitizerTest.php
index c5536b8..8014269 100644
--- a/tests/SanitizerTest.php
+++ b/tests/SanitizerTest.php
@@ -294,4 +294,17 @@ public function testLargeUseDOSattacksAreNullified()
self::assertXmlStringEqualsXmlString($expected, $cleanData);
}
+
+ public function testInvalidNodesAreHandled()
+ {
+ $dataDirectory = __DIR__ . '/data';
+ $initialData = file_get_contents($dataDirectory . '/htmlTest.svg');
+ $expected = file_get_contents($dataDirectory . '/htmlClean.svg');
+
+ $sanitizer = new Sanitizer();
+ $sanitizer->minify(false);
+ $cleanData = $sanitizer->sanitize($initialData);
+
+ self::assertXmlStringEqualsXmlString($expected, $cleanData);
+ }
}
diff --git a/tests/data/entityClean.svg b/tests/data/entityClean.svg
index a7c49b4..01af421 100644
--- a/tests/data/entityClean.svg
+++ b/tests/data/entityClean.svg
@@ -1,4 +1,4 @@
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<svg xmlns="http://www.w3.org/2000/svg">
- <text x="0" y="20" font-size="20">&lab;</text>
+ <text x="0" y="20" font-size="20"></text>
</svg>
diff --git a/tests/data/htmlClean.svg b/tests/data/htmlClean.svg
new file mode 100644
index 0000000..e11c03b
--- /dev/null
+++ b/tests/data/htmlClean.svg
@@ -0,0 +1,2 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="-1 -1 2 2"></svg>
diff --git a/tests/data/htmlTest.svg b/tests/data/htmlTest.svg
new file mode 100644
index 0000000..12bad58
--- /dev/null
+++ b/tests/data/htmlTest.svg
@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="-1 -1 2 2">
+ <!--><img src onerror=alert(1)><!-->
+ <?x ><img src onerror=alert(1)><?x?>
+ <p/><![CDATA[ ><img src onerror=alert(1)> ]]>
+ <font face=""/><![CDATA[ ><img src onerror=alert(1)> ]]>
+</svg>
\ No newline at end of file
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