Maintainers need to be more stringent and vigilant of the code they ship, and core projects that many other projects depend upon should receive better support, financial and otherwise, from users, open source funds and companies alike. This is a fragile ecosystem that this person managed to exploit, and they likely weren't the only one.
I’ve been a package maintainer for a decade. I make it a habit to spot check the source code of every update of every upstream package, hoping that if many others do the same, it might make a difference.
But this backdoor? I wouldn’t have been able to spot it to save my life.
At the end of the day we have to be able to answer why this happened, and how we can prevent it from happening again. It's not about pointing fingers, but about improving the process.
BTW, there have been several attempts at introducing backdoors in the Linux kernel. Some manage to go through, and perhaps we don't know about others, but many were thwarted due to the extreme vigilance of maintainers. Thankfully so, as everyone is well aware of how critical the project is. I'm not saying that all projects have the resources and visibility of Linux, but clearly vigilance is a requirement for lowering the chances of this happening.
> That's assuming a maintainer wasn't compromised, like in this case.
What makes you say that? Everything I've read about this (e.g. [1]) suggests that this was done by someone who also made valid contributions and gained gradual control of the project, where they were allowed to bypass any checks, if they existed at all. The misplaced trust in external contributions, and the lack of a proper peer review process are precisely what allowed this to happen.
[1]: https://boehs.org/node/everything-i-know-about-the-xz-backdo...