From 0597586b89e86e8b4e22080d4c453475057b47b5 Mon Sep 17 00:00:00 2001
From: alecpl <alec@alec.pl>
Date: Wed, 30 Nov 2011 06:35:43 -0500
Subject: [PATCH] - Applied fixes from trunk up to r5512
---
program/steps/mail/get.inc | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 files changed, 54 insertions(+), 5 deletions(-)
diff --git a/program/steps/mail/get.inc b/program/steps/mail/get.inc
index 828f8de..aee2c4d 100644
--- a/program/steps/mail/get.inc
+++ b/program/steps/mail/get.inc
@@ -134,11 +134,24 @@
header("Content-Disposition: $disposition; filename=\"$filename\"");
- // turn off output buffering and print part content
- if ($part->body)
- echo $part->body;
- else if ($part->size)
- $IMAP->get_message_part($MESSAGE->uid, $part->mime_id, $part, true);
+ // do content filtering to avoid XSS through fake images
+ if (!empty($_REQUEST['_embed']) && $browser->ie && $browser->ver <= 8) {
+ if ($part->body)
+ echo preg_match('/<(script|iframe|object)/i', $part->body) ? '' : $part->body;
+ else if ($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');
+ $IMAP->get_message_part($MESSAGE->uid, $part->mime_id, $part, false, $stdout);
+ }
+ }
+ else {
+ // turn off output buffering and print part content
+ if ($part->body)
+ echo $part->body;
+ else if ($part->size)
+ $IMAP->get_message_part($MESSAGE->uid, $part->mime_id, $part, true);
+ }
}
exit;
@@ -166,3 +179,39 @@
exit;
+
+/**
+ * PHP stream filter to detect html/javascript code in attachments
+ */
+class rcube_content_filter extends php_user_filter
+{
+ private $buffer = '';
+ private $cutoff = 2048;
+
+ function onCreate()
+ {
+ $this->cutoff = rand(2048, 3027);
+ return true;
+ }
+
+ function filter($in, $out, &$consumed, $closing)
+ {
+ while ($bucket = stream_bucket_make_writeable($in)) {
+ $this->buffer .= $bucket->data;
+
+ // check for evil content and abort
+ if (preg_match('/<(script|iframe|object)/i', $this->buffer))
+ return PSFS_ERR_FATAL;
+
+ // keep buffer small enough
+ if (strlen($this->buffer) > 4096)
+ $this->buffer = substr($this->buffer, $this->cutoff);
+
+ $consumed += $bucket->datalen;
+ stream_bucket_append($out, $bucket);
+ }
+
+ return PSFS_PASS_ON;
+ }
+}
+
--
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