From 6066ff31980fddc2eb97b987c5bbd1a931495f1e Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishearth@gmail.com>
Date: Thu, 17 Apr 2014 18:37:11 +0200
Subject: Bug 968576: [SECURITY] Dangerous control characters allowed in
 Bugzilla text r=glob a=justdave

---
 Bugzilla/Template.pm                       | 11 +++++++++++
 Bugzilla/Util.pm                           |  4 ++++
 template/en/default/email/bugmail.txt.tmpl |  2 +-
 template/en/default/request/email.txt.tmpl |  2 +-
 4 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/Bugzilla/Template.pm b/Bugzilla/Template.pm
index cd7507963..08999b27a 100644
--- a/Bugzilla/Template.pm
+++ b/Bugzilla/Template.pm
@@ -672,6 +672,17 @@ sub create {
                 my ($data) = @_;
                 return encode_base64($data);
             },
+
+            # Strips out control characters excepting whitespace
+            strip_control_chars => sub {
+                my ($data) = @_;
+                # Only run for utf8 to avoid issues with other multibyte encodings 
+                # that may be reassigning meaning to ascii characters.
+                if (Bugzilla->params->{'utf8'}) {
+                    $data =~ s/(?![\t\r\n])[[:cntrl:]]//g;
+                }
+                return $data;
+            },
             
             # HTML collapses newlines in element attributes to a single space,
             # so form elements which may have whitespace (ie comments) need
diff --git a/Bugzilla/Util.pm b/Bugzilla/Util.pm
index c2dbdc97d..48507ff9e 100644
--- a/Bugzilla/Util.pm
+++ b/Bugzilla/Util.pm
@@ -91,6 +91,10 @@ sub html_quote {
     # Obscure '@'.
     $var =~ s/\@/\&#64;/g;
     if (Bugzilla->params->{'utf8'}) {
+        # Remove control characters if the encoding is utf8.
+        # Other multibyte encodings may be using this range; so ignore if not utf8.
+        $var =~ s/(?![\t\r\n])[[:cntrl:]]//g;
+
         # Remove the following characters because they're
         # influencing BiDi:
         # --------------------------------------------------------
diff --git a/template/en/default/email/bugmail.txt.tmpl b/template/en/default/email/bugmail.txt.tmpl
index 0b349fb15..a3a0b873c 100644
--- a/template/en/default/email/bugmail.txt.tmpl
+++ b/template/en/default/email/bugmail.txt.tmpl
@@ -32,7 +32,7 @@
 [%- IF comment.count %]
 --- Comment #[% comment.count %] from [% comment.author.identity %] ---
 [% END %]
-[%+ comment.body_full({ is_bugmail => 1, wrap => 1 }) %]
+[%+ comment.body_full({ is_bugmail => 1, wrap => 1 }) FILTER strip_control_chars %]
 [% END %]
 
 -- [%# Protect the trailing space of the signature marker %]
diff --git a/template/en/default/request/email.txt.tmpl b/template/en/default/request/email.txt.tmpl
index fb957484b..65946a1e1 100644
--- a/template/en/default/request/email.txt.tmpl
+++ b/template/en/default/request/email.txt.tmpl
@@ -84,7 +84,7 @@ Attachment [% attidsummary %]
 [%-# .defined is necessary to avoid a taint issue in Perl < 5.10.1, see bug 509794. %]
 [% IF Bugzilla.cgi.param("comment").defined && Bugzilla.cgi.param("comment").length > 0 %]
 ------- Additional Comments from [% user.identity %]
-[%+ Bugzilla.cgi.param("comment") %]
+[%+ Bugzilla.cgi.param("comment") FILTER strip_control_chars %]
 [% END %]
 
 [%- END %]
-- 
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