diff --git a/internal/pkg/assets/assets.go b/internal/pkg/assets/assets.go
index 7aad5b42..1312465f 100644
--- a/internal/pkg/assets/assets.go
+++ b/internal/pkg/assets/assets.go
@@ -3,7 +3,9 @@ package assets
 import (
 	"fmt"
 	"github.com/hpcng/warewulf/internal/pkg/config"
+	"github.com/hpcng/warewulf/internal/pkg/util"
 	"github.com/hpcng/warewulf/internal/pkg/vnfs"
+	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	//	"os"
@@ -30,8 +32,8 @@ type nodeGroup struct {
 	Comment        string
 	Vnfs           string
 	Ipxe           string `yaml:"ipxe template"`
-	SystemOverlay  string `yaml:"system system-overlay""`
-	RuntimeOverlay string `yaml:"runtime system-overlay""`
+	SystemOverlay  string `yaml:"system overlay""`
+	RuntimeOverlay string `yaml:"runtime overlay""`
 	DomainSuffix   string `yaml:"domain suffix"`
 	KernelVersion  string `yaml:"kernel version"`
 	KernelArgs	   string `yaml:"kernel args"`
@@ -42,8 +44,8 @@ type nodeEntry struct {
 	Hostname       string
 	Vnfs           string
 	Ipxe           string `yaml:"ipxe template"`
-	SystemOverlay  string `yaml:"system system-overlay"`
-	RuntimeOverlay string `yaml:"runtime system-overlay"`
+	SystemOverlay  string `yaml:"system overlay"`
+	RuntimeOverlay string `yaml:"runtime overlay"`
 	DomainSuffix   string `yaml:"domain suffix"`
 	KernelVersion  string `yaml:"kernel version"`
 	KernelArgs	   string `yaml:"kernel args"`
@@ -80,6 +82,7 @@ func FindAllNodes() ([]NodeInfo, error) {
 	config := config.New()
 
 
+	wwlog.Printf(wwlog.DEBUG, "Opening configuration file: %s\n", ConfigFile)
 	data, err := ioutil.ReadFile(ConfigFile)
 	if err != nil {
 		fmt.Printf("error reading node configuration file\n")
@@ -145,6 +148,14 @@ func FindAllNodes() ([]NodeInfo, error) {
 				n.Fqdn = node.Hostname
 			}
 
+			util.ValidateOrDie(n.Fqdn, "group name", 		n.GroupName, "^[a-zA-Z0-9-._]+$")
+			util.ValidateOrDie(n.Fqdn, "vnfs", 				n.Vnfs, "^[a-zA-Z0-9-._:/]+$")
+			util.ValidateOrDie(n.Fqdn, "system overlay", 	n.SystemOverlay, "^[a-zA-Z0-9-._]+$")
+			util.ValidateOrDie(n.Fqdn, "runtime overlay", 	n.RuntimeOverlay, "^[a-zA-Z0-9-._]+$")
+			util.ValidateOrDie(n.Fqdn, "domain suffix", 	n.DomainName, "^[a-zA-Z0-9-._]+$")
+			util.ValidateOrDie(n.Fqdn, "hostname", 			n.HostName, "^[a-zA-Z0-9-_]+$")
+			util.ValidateOrDie(n.Fqdn, "kernel version", 	n.KernelVersion, "^[a-zA-Z0-9-._]+$")
+
 			v := vnfs.New(n.Vnfs)
 			n.VnfsDir = config.VnfsChroot(v.NameClean())
 
@@ -155,6 +166,7 @@ func FindAllNodes() ([]NodeInfo, error) {
 	return ret, nil
 }
 
+
 func FindByHwaddr(hwa string) (NodeInfo, error) {
 	var ret NodeInfo
 
diff --git a/internal/pkg/config/config.go b/internal/pkg/config/config.go
index eca045dc..92426005 100644
--- a/internal/pkg/config/config.go
+++ b/internal/pkg/config/config.go
@@ -2,11 +2,13 @@ package config
 
 import (
 	"fmt"
+	"github.com/hpcng/warewulf/internal/pkg/util"
 	"github.com/hpcng/warewulf/internal/pkg/wwlog"
 	"github.com/kelseyhightower/envconfig"
 	"gopkg.in/yaml.v2"
 	"io/ioutil"
 	"os"
+	"path"
 )
 
 
@@ -50,45 +52,103 @@ func init() {
 	if c.LocalStateDir == "" {
 		c.LocalStateDir = "/var/warewulf"
 	}
+
+	util.ValidateOrDie("warewulf.conf", "warewulfd ipaddr", c.Ipaddr, "^[0-9]+.[0-9]+.[0-9]+.[0-9]+$")
+	util.ValidateOrDie("warewulf.conf", "system config dir", c.SysConfDir, "^[a-zA-Z0-9-._:/]+$")
+	util.ValidateOrDie("warewulf.conf", "local state dir", c.LocalStateDir, "^[a-zA-Z0-9-._:/]+$")
+
 }
 
 func New() (Config) {
 	return c
 }
 
-func (self *Config) NodeConfig() (string) {
+func (self *Config) NodeConfig() string {
 	return fmt.Sprintf("%s/nodes.conf", self.LocalStateDir)
 }
 
-func (self *Config) SystemOverlaySource(overlayName string) (string) {
-	return fmt.Sprintf("%s/overlays/system/%s", self.LocalStateDir, overlayName)
+func (self *Config) OverlayDir() string {
+	return fmt.Sprintf("%s/overlays/", self.LocalStateDir)
 }
 
-func (self *Config) RuntimeOverlaySource(overlayName string) (string) {
-	return fmt.Sprintf("%s/overlays/runtime/%s", self.LocalStateDir, overlayName)
+func (self *Config) SystemOverlayDir() string {
+	return path.Join(self.OverlayDir(), "/system")
 }
 
-func (self *Config) KernelImage(kernelVersion string) (string) {
+func (self *Config) RuntimeOverlayDir() string {
+	return path.Join(self.OverlayDir(), "/runtime")
+}
+
+func (self *Config) SystemOverlaySource(overlayName string) string {
+	if util.TaintCheck(overlayName, "^[a-zA-Z0-9-._]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "System overlay name contains illegal characters: %s\n", overlayName)
+		os.Exit(1)
+	}
+
+	return path.Join(self.SystemOverlayDir(), overlayName)
+}
+
+
+func (self *Config) RuntimeOverlaySource(overlayName string) string {
+	if util.TaintCheck(overlayName, "^[a-zA-Z0-9-._]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "Runtime overlay name contains illegal characters: %s\n", overlayName)
+		os.Exit(1)
+	}
+
+	return path.Join(self.RuntimeOverlayDir(), overlayName)
+}
+
+func (self *Config) KernelImage(kernelVersion string) string {
+	if util.TaintCheck(kernelVersion, "^[a-zA-Z0-9-._]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "Runtime overlay name contains illegal characters: %s\n", kernelVersion)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/provision/kernel/vmlinuz-%s", self.LocalStateDir, kernelVersion)
 }
 
-func (self *Config) KmodsImage(kernelVersion string) (string) {
+func (self *Config) KmodsImage(kernelVersion string) string {
+	if util.TaintCheck(kernelVersion, "^[a-zA-Z0-9-._]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "Runtime overlay name contains illegal characters: %s\n", kernelVersion)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/provision/kernel/kmods-%s.img", self.LocalStateDir, kernelVersion)
 }
 
-func (self *Config) VnfsImage(vnfsNameClean string) (string) {
+func (self *Config) VnfsImage(vnfsNameClean string) string {
+	if util.TaintCheck(vnfsNameClean, "^[a-zA-Z0-9-._:]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "Runtime overlay name contains illegal characters: %s\n", vnfsNameClean)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/provision/vnfs/%s.img.gz", self.LocalStateDir, vnfsNameClean)
 }
 
-func (self *Config) SystemOverlayImage(nodeName string) (string) {
+func (self *Config) SystemOverlayImage(nodeName string) string {
+	if util.TaintCheck(nodeName, "^[a-zA-Z0-9-._:]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "System overlay name contains illegal characters: %s\n", nodeName)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/provision/overlays/system/%s.img", self.LocalStateDir, nodeName)
 }
 
-func (self *Config) RuntimeOverlayImage(nodeName string) (string) {
+func (self *Config) RuntimeOverlayImage(nodeName string) string {
+	if util.TaintCheck(nodeName, "^[a-zA-Z0-9-._:]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "System overlay name contains illegal characters: %s\n", nodeName)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/provision/overlays/runtime/%s.img", self.LocalStateDir, nodeName)
 }
 
-func (self *Config) VnfsChroot(vnfsNameClean string) (string) {
+func (self *Config) VnfsChroot(vnfsNameClean string) string {
+	if util.TaintCheck(vnfsNameClean, "^[a-zA-Z0-9-._:]+$") == false {
+		wwlog.Printf(wwlog.ERROR, "Runtime overlay name contains illegal characters: %s\n", vnfsNameClean)
+		os.Exit(1)
+	}
+
 	return fmt.Sprintf("%s/chroot/%s.img", self.LocalStateDir, vnfsNameClean)
 }