The SRX Network Security Daemon (nsd) in Juniper SRX Series services gateways with Junos 12.1X44 before 12.1X44-D50, 12.1X46 before 12.1X46-D35, 12.1X47 before 12.1X47-D25, and 12.3X48 before 12.3X48-D15 allows remote DNS servers to cause a denial of service (crash) via a crafted DNS response.