CVE-2016-4068 (Other, published 2017-04-13T14:59Z)
Description: value: Cross-site scripting (XSS) vulnerability in Roundcube Webmail before 1.0.9 and 1.1.x before 1.1.5 allows remote attackers to inject arbitrary web script or HTML via a crafted SVG, a different vulnerability than CVE-2015-8864.
Severity: MEDIUM (CVSS v3 base score: 6.1)
Weakness: CWE-79 \u2014 Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.
Repository: https://github.com/roundcube/roundcubemail
Files changed:
CHANGELOG
program/steps/mail/get.inc
Commit message: Fix XSS issue in SVG images handling (#1490625)


Vulnerable code:
                if ($saved) {
            // do content filtering to avoid XSS through fake images
            else if (!empty($_REQUEST['_embed']) && $browser->ie && $browser->ver <= 8) {
                if ($body) {
                    echo preg_match('/<(script|iframe|object)/i', $body) ? '' : $body;
                    $sent = true;
                }
                else if ($part->size) {
                    $stdout = fopen('php://output', 'w');
                    stream_filter_register('rcube_content', 'rcube_content_filter') or die('Failed to register content filter');
                    stream_filter_append($stdout, 'rcube_content');
                    $sent = $MESSAGE->get_part_body($part->mime_id, true, 0, $stdout);
                }
            }
            // send part as-it-is
                if ($body && empty($plugin['download'])) {
                    header("Content-Length: " . strlen($body));
                    echo $body;
                    $sent = true;
                }
                else if ($part->size) {
                    // Don't be tempted to set Content-Length to $part->d_parameters['size'] (#1490482)
                    // RFC2183 says "The size parameter indicates an approximate size"

                    $sent = $MESSAGE->get_part_body($part->mime_id, false, 0, -1);
                }

Fixed code:
- Fix XSS issue in SVG images handling (#1490625)
                else if (stripos($mimetype, 'image/svg') === 0) {
                    $content = rcmail_svg_filter(file_get_contents($orig_name));
                    file_put_contents($cache_file, $content);
                    unlink($orig_name);
                }
                if ($sent = $saved) {
                $sent = rcmail_message_part_output($body, $part, $mimetype, $plugin['download']);

/**
 * Output attachment body with content filtering
 */
function rcmail_message_part_output($body, $part, $mimetype, $download)
{
    global $MESSAGE, $RCMAIL;

    if (!$part->size && !$body) {
        return false;
    }

    $browser = $RCMAIL->output->browser;
    $secure  = stripos($mimetype, 'image/') === false || $download;

    // Remove <script> in SVG images
    if (!$secure && stripos($mimetype, 'image/svg') === 0) {
        if (!$body) {
            $body = $MESSAGE->get_part_body($part->mime_id, false);
            if (empty($body)) {
                return false;
            }
        }

        echo rcmail_svg_filter($body);
        return true;
    }

    // Remove dangerous content in images for older IE (to be removed)
    if (!$secure && $browser->ie && $browser->ver <= 8) {
        if ($body) {
            echo preg_match('/<(script|iframe|object)/i', $body) ? '' : $body;
            return true;
        }
        else {
            $stdout = fopen('php://output', 'w');
            stream_filter_register('rcube_content', 'rcube_content_filter') or die('Failed to register content filter');
            stream_filter_append($stdout, 'rcube_content');
            return $MESSAGE->get_part_body($part->mime_id, true, 0, $stdout);
        }
    }

    if ($body && !$download) {
        header("Content-Length: " . strlen($body));
        echo $body;
        return true;
    }

    // Don't be tempted to set Content-Length to $part->d_parameters['size'] (#1490482)
    // RFC2183 says "The size parameter indicates an approximate size"

    return $MESSAGE->get_part_body($part->mime_id, false, 0, -1);
}

/**
 * Remove <script> in SVG images
 */
function rcmail_svg_filter($body)
{
    $dom = new DOMDocument;
    $dom->loadXML($body);

    foreach ($dom->getElementsByTagName('script') as $node) {
        $node->parentNode->removeChild($node);
    }

    return $dom->saveXML() ?: '';
}