Dear security team, In a recent post roundcube webmail upstream has announced the following security fix for #968216:
Cross-site scripting (XSS) via HTML messages with malicious SVG
or math content (CVE-2020-16145)
AFAICT CVE-2020-16145 is only about SVG not math, but the upstream
commit addresses both so I opened a single bug:
https://github.com/roundcube/roundcubemail/commit/589d36010048300ed39f4887aab1afd3ae98d00e
Debdiff tested and attached, but I'd appreciate if you could take care
of the DLA :-)
Thanks!
Cheers,
--
Guilhem.
diffstat for roundcube-1.2.3+dfsg.1 roundcube-1.2.3+dfsg.1
changelog | 8 +++
patches/CVE-2020-16145.patch | 107 +++++++++++++++++++++++++++++++++++++++++++
patches/series | 1
3 files changed, 116 insertions(+)
diff -Nru roundcube-1.2.3+dfsg.1/debian/changelog
roundcube-1.2.3+dfsg.1/debian/changelog
--- roundcube-1.2.3+dfsg.1/debian/changelog 2020-07-06 16:14:59.000000000
+0200
+++ roundcube-1.2.3+dfsg.1/debian/changelog 2020-08-11 18:38:40.000000000
+0200
@@ -1,3 +1,11 @@
+roundcube (1.2.3+dfsg.1-4+deb9u7) stretch-security; urgency=high
+
+ * Backport security fix for CVE-2020-16145: Cross-site scripting (XSS)
+ vulnerability via HTML messages with malicious svg or math
+ content. (Closes: #968216)
+
+ -- Guilhem Moulin <guil...@debian.org> Tue, 11 Aug 2020 18:38:40 +0200
+
roundcube (1.2.3+dfsg.1-4+deb9u6) stretch; urgency=high
* Backport security fix for CVE-2020-15562: Cross-Site Scripting (XSS)
diff -Nru roundcube-1.2.3+dfsg.1/debian/patches/CVE-2020-16145.patch
roundcube-1.2.3+dfsg.1/debian/patches/CVE-2020-16145.patch
--- roundcube-1.2.3+dfsg.1/debian/patches/CVE-2020-16145.patch 1970-01-01
01:00:00.000000000 +0100
+++ roundcube-1.2.3+dfsg.1/debian/patches/CVE-2020-16145.patch 2020-08-11
18:38:40.000000000 +0200
@@ -0,0 +1,107 @@
+commit 589d36010048300ed39f4887aab1afd3ae98d00e
+Author: Aleksander Machniak <a...@alec.pl>
+Date: Sun Aug 9 18:02:16 2020 +0200
+
+ Fix cross-site scripting (XSS) via HTML messages with malicious svg or
math content
+
+diff --git a/program/lib/Roundcube/rcube_washtml.php
b/program/lib/Roundcube/rcube_washtml.php
+index 4c5ca46a3..81a3edf1b 100644
+--- a/program/lib/Roundcube/rcube_washtml.php
++++ b/program/lib/Roundcube/rcube_washtml.php
+@@ -365,7 +365,30 @@ class rcube_washtml
+ return $this->config['blocked_src'];
+ }
+ }
+- else if (preg_match('/^data:image.+/i', $uri)) { // RFC2397
++ else if (preg_match('/^data:image\/([^,]+),(.+)$/i', $uri, $matches))
{ // RFC2397
++ // svg images can be insecure, we'll sanitize them
++ if (stripos($matches[1], 'svg') !== false) {
++ $svg = $matches[2];
++
++ if (stripos($matches[1], ';base64') !== false) {
++ $svg = base64_decode($svg);
++ $type = $matches[1];
++ }
++ else {
++ $type = $matches[1] . ';base64';
++ }
++
++ $washer = new self($this->config);
++ $svg = $washer->wash($svg);
++
++ // Invalid svg content
++ if (empty($svg)) {
++ return null;
++ }
++
++ return 'data:image/' . $type . ',' . base64_encode($svg);
++ }
++
+ return $uri;
+ }
+ }
+@@ -375,7 +398,7 @@ class rcube_washtml
+ */
+ private function is_link_attribute($tag, $attr)
+ {
+- return ($tag == 'a' || $tag == 'area') && $attr == 'href';
++ return $attr === 'href';
+ }
+
+ /**
+@@ -387,6 +410,7 @@ class rcube_washtml
+ || $attr == 'color-profile' // SVG
+ || ($attr == 'poster' && $tag == 'video')
+ || ($attr == 'src' && preg_match('/^(img|source)$/i', $tag))
++ || ($tag == 'use' && $attr == 'href') // SVG
+ || ($tag == 'image' && $attr == 'href'); // SVG
+ }
+
+@@ -399,6 +423,31 @@ class rcube_washtml
+ 'marker-end', 'marker-mid', 'clip-path', 'mask', 'cursor'));
+ }
+
++ /**
++ * Check if a specified element has an attribute with specified value.
++ * Do it in case-insensitive manner.
++ *
++ * @param DOMElement $node The element
++ * @param string $attr_name The attribute name
++ * @param string $attr_value The attribute value to find
++ *
++ * @return bool True if the specified attribute exists and has the
expected value
++ */
++ private static function attribute_value($node, $attr_name, $attr_value)
++ {
++ $attr_name = strtolower($attr_name);
++
++ foreach ($node->attributes as $name => $attr) {
++ if (strtolower($name) === $attr_name) {
++ if (strtolower($attr_value) === strtolower($attr->nodeValue))
{
++ return true;
++ }
++ }
++ }
++
++ return false;
++ }
++
+ /**
+ * The main loop that recurse on a node tree.
+ * It output only allowed tags with allowed attributes and allowed inline
styles
+@@ -433,6 +482,15 @@ class rcube_washtml
+ switch ($node->nodeType) {
+ case XML_ELEMENT_NODE: //Check element
+ $tagName = strtolower($node->tagName);
++
++ if (in_array($tagName, array('animate', 'animatecolor',
'set', 'animatetransform'))
++ && self::attribute_value($node, 'attributename', 'href')
++ ) {
++ // Insecure svg tags
++ $dump .= "<!-- $tagName blocked -->";
++ break;
++ }
++
+ if ($callback = $this->handlers[$tagName]) {
+ $dump .= call_user_func($callback, $tagName,
+ $this->wash_attribs($node), $this->dumpHtml($node,
$level), $this);
diff -Nru roundcube-1.2.3+dfsg.1/debian/patches/series
roundcube-1.2.3+dfsg.1/debian/patches/series
--- roundcube-1.2.3+dfsg.1/debian/patches/series 2020-07-06
16:14:59.000000000 +0200
+++ roundcube-1.2.3+dfsg.1/debian/patches/series 2020-08-11
18:38:40.000000000 +0200
@@ -21,3 +21,4 @@
CVE-2020-13964.patch
CVE-2020-13965.patch
CVE-2020-15562.patch
+CVE-2020-16145.patch
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