1. Vulnerability Description

• If you use “:+” to apply to a list with an imputable attribute, performance may be compromised.

2. Vulnerability Countermeasure

• If you frequently use append, you should use the ListBuffer, which has an Append cost of O(1).

3. Example Code

• Vulnerable code

class Test {
   val a = List("list")
   a :+ "oh no"
}

• Safe code

import scala.collection.mutable.ListBuffer 
class Test {
   var name = ListBuffer[String]()   
   name += "good"
   name += "oh good"
}