Programming is a very important aspect of this job role. All you do while working as a Source Code Auditor is look at the code and find a weakness in it. You must have in-depth knowledge of programming language. If you think you are weak in programming languages, I suggest you start working on it. The most important programming languages you need to know about are C/C++, C#, Java/JSP, .NET, Perl, PHP, Ruby, Python.
Other skills helpful would be:
- CERT/CC, MITRE, Sun and NIST secure coding guidelines and standards
- Software and web application development practices
- Penetration testing and vulnerability assessments