His point is that in security, the opposite applies. The supposed "incompetence" is just plausible deniability for a malicious act.
It's really a matter of context. Security people tend to only be involved when things are already nefarious where as boring old normal people like us see get to see the mundane everyday mistakes so not just the nefarious bits.
It's possible the backdoor is deliberate, I have no idea in this particular case, but the more likely situation, absent more information, is that someone who is earning a middling wage just added the "feature" and didn't think about the security implications because no one cares about computer security.
I work heavily with security-conscious clients where vulnerabilities would be catastrophic. And we are talking high profile clients that are juicy target for attacks.
My experience is still that the vast majority of vulnerabilities are accidental rather than due to malice.
And when I say “vast”, I mean the so heavily slanted in favour of “unintended” that it’s not even comparable.
> It's really a matter of context. Security people tend to only be involved when things are already nefarious
I’m guessing you’ve not worked with many “security people”?
You’d be surprised how much of their day-to-day is mundane.
I know their day to day is just as mundane as the rest of ours it's their "Step 1" approach that i've seen to be entirely different. I assume it's probably a software bug, they assume it's an exploit.
They're not mutually exclusive.
I suspect you and the security team are arguing the same thing but with different terminology.
When vulnerabilities (which, in the vast majority of cases, are accidental) are published, or when static analysis tools review code, you'll get a description and a severity score. That description will broadly describe how, if possible, that vulnerability can be exploited.
Working for an in-house security team basically just means you're a risk assessor. And the way you assess risks is to look at the potential consequences of those risks. Which means looking at how bugs can be exploited.
But none of this means those vulnerabilities were placed in the code intentionally and with malice. It just means that someone else who is malicious could, theoretically, exploit those vulnerabilities. And if the risk of that is greater than the risk appetite of the business (as will typically be the case), then they'll feedback to you that there is an exploitable vulnerability that you need to patch.