fix (exp shim-pwn): #104 merged directory appears twice in path (#108)

pkg/exploit/escaping/containerd_shim_pwn.go

@@ -26,6 +26,7 @@ import (
 	"log"
 	"net"
 	"os"
+	"path/filepath"
 	"regexp"
 	"strings"
 
@@ -123,7 +124,9 @@ func containerdShimApiExp(sock, shellCmd, rhost, rport string) error {
 	localBundlePath := fmt.Sprintf("/cdk_%s", util.RandString(6))
 	os.Mkdir(localBundlePath, os.ModePerm)
 
-	dockerAbsPath := GetDockerAbsPath() + "/merged" + localBundlePath
+	absPath := GetDockerAbsPath()
+	absPath = strings.TrimSuffix(absPath, "/merged")
+	dockerAbsPath := filepath.Join(absPath, "merged", localBundlePath)
 
 	var payloadShellCmd = ""
 	if len(shellCmd) > 0 {