This was a coding error in one of the pieces on the back end.

这是后端部分的一个编码错误。

I'm going to return an error code.

我将返回一个错误代码。

Heartbleed is not a virus, it's a coding error that is so small and so simple that it took two years for anyone to even notice it.

Heartbleed 不是病毒，它是一个编码错误， 它非常小而且非常简单， 以至于人们花了两年时间才注意到它。