From ad1c95f23551ca4bbd459f6a6d73dfd68f24ee9a Mon Sep 17 00:00:00 2001
From: Jakub Narebski <jnareb@gmail.com>
Date: Wed, 15 Dec 2010 00:34:01 +0100
Subject: gitweb: Introduce esc_attr to escape attributes of HTML elements

It is needed only to escape attributes of handcrafted HTML elements,
and not those generated using CGI.pm subroutines / methods for HTML
generation.

While at it, add esc_url and esc_html where needed, and prefer to use
CGI.pm HTML generating methods than handcrafted HTML code.  Most of
those are probably unnecessary (could be exploited only by person with
write access to gitweb config, or at least access to the repository).

This fixes CVE-2010-3906

Reported-by: Emanuele Gentili <e.gentili@tigersecurity.it>
Helped-by: John 'Warthog9' Hawley <warthog9@kernel.org>
Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Jakub Narebski <jnareb@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
(cherry picked from commit 3017ed62f47ce14a959e2d315c434d4980cf4243)

Conflicts:

	gitweb/gitweb.perl

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>

[For Ubuntu maverick, this patch has been slightly modified,
 so that hunk 8 applies cleanly; in the debian unstable version
 (1:1.7.2.3-2.2) this patch is pulled from a patch w/git id
 d905742e7d9632cbb3ce3f309d429d3dadc448d0 to make the logo optional.

Signed-off-by: Steve Beattie <sbeattie@ubuntu.com>
 ]

---
 gitweb/gitweb.perl |   37 ++++++++++++++++++++++---------------
 1 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
index 348f94b..dfa5966 100755
--- a/gitweb/gitweb.perl
+++ b/gitweb/gitweb.perl
@@ -1332,6 +1332,13 @@ sub esc_url {
 	return $str;
 }
 
+# quote unsafe characters in HTML attributes
+sub esc_attr {
+
+	# for XHTML conformance escaping '"' to '&quot;' is not enough
+	return esc_html(@_);
+}
+
 # replace invalid utf8 character with SUBSTITUTION sequence
 sub esc_html {
 	my $str = shift;
@@ -1737,7 +1744,7 @@ sub format_ref_marker {
 					hash=>$dest
 				)}, $name);
 
-			$markers .= " <span class=\"$class\" title=\"$ref\">" .
+			$markers .= " <span class=\"".esc_attr($class)."\" title=\"".esc_attr($ref)."\">" .
 				$link . "</span>";
 		}
 	}
@@ -1821,7 +1828,7 @@ sub git_get_avatar {
 		return $pre_white .
 		       "<img width=\"$size\" " .
 		            "class=\"avatar\" " .
-		            "src=\"$url\" " .
+		            "src=\"".esc_url($url)."\" " .
 			    "alt=\"\" " .
 		       "/>" . $post_white;
 	} else {
@@ -2532,7 +2539,7 @@ sub git_show_project_tagcloud {
 	} else {
 		my @tags = sort { $cloud->{$a}->{count} <=> $cloud->{$b}->{count} } keys %$cloud;
 		return '<p align="center">' . join (', ', map {
-			"<a href=\"$home_link?by_tag=$_\">$cloud->{$_}->{topname}</a>"
+			$cgi->a({-href=>"$home_link?by_tag=$_"}, $cloud->{$_}->{topname})
 		} splice(@tags, 0, $count)) . '</p>';
 	}
 }
@@ -3429,11 +3436,11 @@ EOF
 	# print out each stylesheet that exist, providing backwards capability
 	# for those people who defined $stylesheet in a config file
 	if (defined $stylesheet) {
-		print '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'"/>'."\n";
+		print '<link rel="stylesheet" type="text/css" href="'.esc_url($stylesheet).'"/>'."\n";
 	} else {
 		foreach my $stylesheet (@stylesheets) {
 			next unless $stylesheet;
-			print '<link rel="stylesheet" type="text/css" href="'.$stylesheet.'"/>'."\n";
+			print '<link rel="stylesheet" type="text/css" href="'.esc_url($stylesheet).'"/>'."\n";
 		}
 	}
 	if (defined $project) {
@@ -3446,7 +3453,7 @@ EOF
 			my $type = lc($format);
 			my %link_attr = (
 				'-rel' => 'alternate',
-				'-title' => "$project - $href_params{'-title'} - $format feed",
+				'-title' => esc_attr("$project - $href_params{'-title'} - $format feed"),
 				'-type' => "application/$type+xml"
 			);
 
@@ -3473,13 +3480,13 @@ EOF
 	} else {
 		printf('<link rel="alternate" title="%s projects list" '.
 		       'href="%s" type="text/plain; charset=utf-8" />'."\n",
-		       $site_name, href(project=>undef, action=>"project_index"));
+		       esc_attr($site_name), href(project=>undef, action=>"project_index"));
 		printf('<link rel="alternate" title="%s projects feeds" '.
 		       'href="%s" type="text/x-opml" />'."\n",
-		       $site_name, href(project=>undef, action=>"opml"));
+		       esc_attr($site_name), href(project=>undef, action=>"opml"));
 	}
 	if (defined $favicon) {
-		print qq(<link rel="shortcut icon" href="$favicon" type="image/png" />\n);
+		print qq(<link rel="shortcut icon" href=").esc_url($favicon).qq(" type="image/png" />\n);
 	}
 
 	print "</head>\n" .
@@ -3493,7 +3500,7 @@ EOF
 	print "<div class=\"page_header\">\n" .
 	      $cgi->a({-href => esc_url($logo_url),
 	               -title => $logo_label},
-	              qq(<img src="$logo" width="72" height="27" alt="git" class="logo"/>));
+		      qq(<img src=").esc_url($logo).qq(" width="72" height="27" alt="git" class="logo"/>));
 	print $cgi->a({-href => esc_url($home_link)}, $home_link_str) . " / ";
 	if (defined $project) {
 		print $cgi->a({-href => href(action=>"summary")}, esc_html($project));
@@ -5612,14 +5619,14 @@ sub git_blob {
 	} else {
 		print "<div class=\"page_nav\">\n" .
 		      "<br/><br/></div>\n" .
-		      "<div class=\"title\">$hash</div>\n";
+		      "<div class=\"title\">".esc_html($hash)."</div>\n";
 	}
 	git_print_page_path($file_name, "blob", $hash_base);
 	print "<div class=\"page_body\">\n";
 	if ($mimetype =~ m!^image/!) {
-		print qq!<img type="$mimetype"!;
+		print qq!<img type="!.esc_attr($mimetype).qq!"!;
 		if ($file_name) {
-			print qq! alt="$file_name" title="$file_name"!;
+			print qq! alt="!.esc_attr($file_name).qq!" title="!.esc_attr($file_name).qq!"!;
 		}
 		print qq! src="! .
 		      href(action=>"blob_plain", hash=>$hash,
@@ -5694,7 +5701,7 @@ sub git_tree {
 		undef $hash_base;
 		print "<div class=\"page_nav\">\n";
 		print "<br/><br/></div>\n";
-		print "<div class=\"title\">$hash</div>\n";
+		print "<div class=\"title\">".esc_html($hash)."</div>\n";
 	}
 	if (defined $file_name) {
 		$basedir = $file_name;
@@ -6162,7 +6169,7 @@ sub git_blobdiff {
 			git_print_header_div('commit', esc_html($co{'title'}), $hash_base);
 		} else {
 			print "<div class=\"page_nav\"><br/>$formats_nav<br/></div>\n";
-			print "<div class=\"title\">$hash vs $hash_parent</div>\n";
+			print "<div class=\"title\">".esc_html("$hash vs $hash_parent")."</div>\n";
 		}
 		if (defined $file_name) {
 			git_print_page_path($file_name, "blob", $hash_base);
-- 
1.7.2.3