Commits

Anonymous committed 3017ed6

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>

Comments (0)

Files changed (1)

gitweb/gitweb.perl

 	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 $str = shift;
 					hash=>$dest
 				)}, $name);
 
-			$markers .= " <span class=\"$class\" title=\"$ref\">" .
+			$markers .= " <span class=\"".esc_attr($class)."\" title=\"".esc_attr($ref)."\">" .
 				$link . "</span>";
 		}
 	}
 		return $pre_white .
 		       "<img width=\"$size\" " .
 		            "class=\"avatar\" " .
-		            "src=\"$url\" " .
+		            "src=\"".esc_url($url)."\" " .
 			    "alt=\"\" " .
 		       "/>" . $post_white;
 	} else {
 	} 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>';
 	}
 }
 	# 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) {
 			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"
 			);
 
 	} 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" .
 	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));
 	} 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,
 		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 = $file_name;
 			git_print_header_div('commit', esc_html($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);