CVE-2023-28100: TIOCLINUX can send commands outside sandbox if running on a virtual console

[Simon McVittie]

https://github.com/flatpak/flatpak/security/advisories/GHSA-7qpw-3vjv-xrqp

Fixed in 1.15.4, 1.10.x >= 1.10.8, 1.12.x >= 1.12.8, 1.14.x >= 1.14.4. At the time of writing, mantic and noble are OK but jammy, focal and bionic are likely to be vulnerable.

(This is a relatively low-impact vulnerability because it's unusual to run flatpak from a Linux virtual console.)