Common Weakness Enumeration (CWE) is a list containing the top 25 most dangerous programming errors that can lead to serious software vulnerabilities.
You can find the list at: http://cwe.mitre.org/top25/
It should be common sense for every programmer but still software is released violating these basic rules. The list serves as reminder for senior developers and can be used as a checklist by CIO’s. For junior developers it can be considered as a reference of good practices and pitfalls to avoid.