Bug 513593: Make the WebService taint incoming parameters

Bugzilla/Install/Requirements.pm

@@ -233,6 +233,12 @@ sub OPTIONAL_MODULES {
         feature => ['jsonrpc'],
     },
     {
+        package => 'Test-Taint',
+        module  => 'Test::Taint',
+        version => 0,
+        feature => ['jsonrpc', 'xmlrpc'],
+    },
+    {
         # We need the 'utf8_mode' method of HTML::Parser, for HTML::Scrubber.
         package => 'HTML-Parser',
         module  => 'HTML::Parser',

Bugzilla/WebService/Server/JSONRPC.pm

@@ -26,6 +26,7 @@ use base qw(JSON::RPC::Server::CGI Bugzilla::WebService::Server);
 
 use Bugzilla::Error;
 use Bugzilla::WebService::Constants;
+use Bugzilla::WebService::Util qw(taint_data);
 use Date::Parse;
 use DateTime;
 
@@ -123,6 +124,8 @@ sub _argument_type_check {
         $params = $params->[0];
     }
 
+    taint_data($params);
+
     # Now, convert dateTime fields on input.
     $self->_bz_method_name =~ /^(\S+)\.(\S+)$/;
     my ($class, $method) = ($1, $2);

Bugzilla/WebService/Server/XMLRPC.pm

@@ -68,6 +68,18 @@ eval { require XMLRPC::Lite; };
 our @ISA = qw(XMLRPC::Deserializer);
 
 use Bugzilla::Error;
+use Scalar::Util qw(tainted);
+
+sub deserialize {
+    my $self = shift;
+    my ($xml) = @_;
+    my $som = $self->SUPER::deserialize(@_);
+    if (tainted($xml)) {
+        $som->{_bz_do_taint} = 1;
+    }
+    bless $som, 'Bugzilla::XMLRPC::SOM';
+    return $som;
+}
 
 # Some method arguments need to be converted in some way, when they are input.
 sub decode_value {
@@ -126,6 +138,23 @@ sub _validation_subs {
 
 1;
 
+package Bugzilla::XMLRPC::SOM;
+use strict;
+eval { require XMLRPC::Lite; };
+our @ISA = qw(XMLRPC::SOM);
+use Bugzilla::WebService::Util qw(taint_data);
+
+sub paramsin {
+    my $self = shift;
+    my $params = $self->SUPER::paramsin(@_);
+    if ($self->{_bz_do_taint}) {
+        taint_data($params);
+    }
+    return $params;
+}
+
+1;
+
 # This package exists to fix a UTF-8 bug in SOAP::Lite.
 # See http://rt.cpan.org/Public/Bug/Display.html?id=32952.
 package Bugzilla::XMLRPC::Serializer;

Bugzilla/WebService/Util.pm

@@ -21,10 +21,17 @@
 
 package Bugzilla::WebService::Util;
 use strict;
-
 use base qw(Exporter);
 
-our @EXPORT_OK = qw(filter validate);
+# We have to "require", not "use" this, because otherwise it tries to
+# use features of Test::More during import().
+require Test::Taint;
+
+our @EXPORT_OK = qw(
+    filter 
+    taint_data
+    validate
+);
 
 sub filter ($$) {
     my ($params, $hash) = @_;
@@ -44,6 +51,32 @@ sub filter ($$) {
     return \%newhash;
 }
 
+sub taint_data {
+    my $params = shift;
+    return if !$params;
+    # Though this is a private function, it hasn't changed since 2004 and
+    # should be safe to use, and prevents us from having to write it ourselves
+    # or require another module to do it.
+    Test::Taint::_deeply_traverse(\&_delete_bad_keys, $params);
+    Test::Taint::taint_deeply($params);
+}
+
+sub _delete_bad_keys {
+    foreach my $item (@_) {
+        next if ref $item ne 'HASH';
+        foreach my $key (keys %$item) {
+            # Making something a hash key always untaints it, in Perl.
+            # However, we need to validate our argument names in some way.
+            # We know that all hash keys passed in to the WebService will 
+            # match \w+, so we delete any key that doesn't match that.
+            if ($key !~ /^\w+$/) {
+                delete $item->{$key};
+            }
+        }
+    }
+    return @_;
+}
+
 sub validate  {
     my ($self, $params, @keys) = @_;