I'm writing this on a private branch, it won't be posted until a week from now when the security hole is disclosed.

Security is not compositional. You can have one good feature, and add another good feature, and the result is not two good features, but a new security hole. In this case ?security/CVE-2018-10857 and CVE-2018-10859. And it can be hard to spot this kind of security hole, but then once it's known it seems blindly obvious.

It came to me last night and by this morning I had decided the potential impact was large enough to do a coordinated disclosure. Spent the first half of the day thinking through ways to fix it that don't involve writing my own http library. Then started getting in touch with all the distributions' security teams. And then coded up a fairly complete fix for the worst part of the security hole, although a secondary part is going to need considerably more work.

It looks like the external special remotes are going to need at least some security review too, and I'm still thinking that part of the problem over.


Today's work was sponsored by Trenton Cronholm on Patreon.