It is 100% possible for humans to write utterly secure code in &#x27;C&#x27;. The vast majority of practices which make code not open to  memory exploits were common in the <i>1980s</i> - the late &#x27;80s, anyway. Yes, there were virii even then.<p>Now, is this common? I have no idea. A great deal of &#x27;C&#x27; code never sees the larger Internet anyway.