They do have a poor track record with the language runtime.
You should be concerned about the quality of your language runtime.
MRI, for instance, has had many memory corruption flaws that were plausibly exposed to hostile input. When security is a priority, I advise using JRuby (it helps that JRuby is better than MRI anyways).
But either way: language runtimes for mainstream languages are high-priority targets. Your C code is not. You will not learn the worst problems in your C code until long after it's been deployed.
You should be concerned about the quality of your language runtime.
MRI, for instance, has had many memory corruption flaws that were plausibly exposed to hostile input. When security is a priority, I advise using JRuby (it helps that JRuby is better than MRI anyways).
But either way: language runtimes for mainstream languages are high-priority targets. Your C code is not. You will not learn the worst problems in your C code until long after it's been deployed.