 <ol> <li>Allocating memory with <code>new/new[]/malloc</code> and not freeing it</li> <li>Allocating memory to some pointer and overwrite it accidently e.g. <code>p = new int; p = new int[1];</code></li> <li>Allocating memory in air. i.e. <code>new int[100];</code> or <code>cout&lt;&lt;(*new string("hello"))&lt;&lt;endl;</code></li> </ol>