Bug 1031035: xmlrpc can be DoS'd with billion laughs attack

2 files changed, 11 insertions, 0 deletions

diff --git a/Bugzilla/WebService/Server/XMLRPC.pm b/Bugzilla/WebService/Server/XMLRPC.pm
index 69ba4c0d8..834ea60bf 100644
--- a/Bugzilla/WebService/Server/XMLRPC.pm
+++ b/Bugzilla/WebService/Server/XMLRPC.pm
@@ -140,6 +140,14 @@ use Bugzilla::WebService::Constants qw(XMLRPC_CONTENT_TYPE_WHITELIST);
 use Bugzilla::WebService::Util qw(fix_credentials);
 use Scalar::Util qw(tainted);
 
+sub new {
+    my $self = shift->SUPER::new(@_);
+    # Initialise XML::Parser to not expand references to entities, to prevent DoS
+    require XML::Parser;
+    $self->{_parser}->parser(parser => XML::Parser->new( NoExpand => 1, Handlers => { Default => sub {} } ));
+    return $self;
+}
+
 sub deserialize {
     my $self = shift;
 
diff --git a/importxml.pl b/importxml.pl
index 19be9a61a..63004af6f 100755
--- a/importxml.pl
+++ b/importxml.pl
@@ -1278,6 +1278,9 @@ my $twig = XML::Twig->new(
     },
     start_tag_handlers => { bugzilla => \&init }
 );
+# Prevent DoS using the billion laughs attack.
+$twig->{NoExpand} = 1;
+
 $twig->parse($xml);
 my $root       = $twig->root;
 my $maintainer = $root->{'att'}->{'maintainer'};