3. Is this OSS attack method (including social engineering maintainers) totally unexpected?
No, this is not an unexpected attack - many folks in the industry have been talking about the risk of open source maintainer burn out for years. There’s a commonly shared xkcd cartoon (called "Dependency") people use to describe this vulnerability all the time.
I even gave a talk in 2018 at the
@NodeSummit about how social engineering could be used to target open source security maintainers, gain trust, and infiltrate libraries with vulnerabilities in exactly the way it was used by this attacker.
What is surprising here are the potential lengths the attacker went to over the course of multiple years to develop enough trust to pull this attack off.
ALT Rachel Tobac giving a talk at Node Summit in 2018 discussing the ways attackers could social engineer open source security maintainers to gain the ability to introduce vulnerabilities and attack at scale.
ALT Rachel Tobac in 2018 at Node Summit giving a talk about the likely targets social engineers would consider attacking to build trust and introduce vulnerabilities into open source code that is run by millions of people.