TLDR: this vulnerability does appear to allow an attacker to potentially gain remote root access on vulnerable Linux systems running OpenSSH, with some important caveats:

1. It affects OpenSSH versions 8.5p1 to 9.7p1 on glibc-based Linux systems.

2. The exploit is not 100% reliable - it requires winning a race condition.

3. On a modern system (Debian 12.5.0 from 2024), the researchers estimate it takes: - ~3-4 hours on average to win the race condition - ~6-8 hours on average to obtain a remote root shell (due to ASLR)

4. It requires certain conditions: - The system must be using glibc (not other libc implementations) - 100 simultaneous SSH connections must be allowed (MaxStartups setting) - LoginGraceTime must be set to a non-zero value (default is 120 seconds)

5. The researchers demonstrated working exploits on i386 systems. They believe it's likely exploitable on amd64 systems as well, but hadn't completed that work yet.

6. It's been patched in OpenSSH 9.8p1 released in June 2024.