diff --git a/PVE/QemuServer/OVF.pm b/PVE/QemuServer/OVF.pm
index 0376cbf5..b97b0520 100644
--- a/PVE/QemuServer/OVF.pm
+++ b/PVE/QemuServer/OVF.pm
@@ -221,10 +221,11 @@ ovf:Item[rasd:InstanceID='%s']/rasd:ResourceType", $controller_id);
 	    die "error parsing $filepath, file seems not to exist at $backing_file_path\n";
 	}
 
-	my $virtual_size;
-	if ( !($virtual_size = PVE::Storage::file_size_info($backing_file_path)) ) {
-	    die "error parsing $backing_file_path, size seems to be $virtual_size\n";
-	}
+	($backing_file_path) = $backing_file_path =~ m|^(/.*)|; # untaint
+
+	my $virtual_size = PVE::Storage::file_size_info($backing_file_path);
+	die "error parsing $backing_file_path, cannot determine file size\n"
+	    if !$virtual_size;
 
 	$pve_disk = {
 	    disk_address => $pve_disk_address,