Lead · Vulnerabilities
Key-only authentication was a claim, not a control, and it has been a claim since 2016
OpenSSH has shipped an emergency fix after researchers found that on musl-based Linux, a password between 257 and 1,024 bytes logs you straight into accounts that have no password at all.
The bug is called "*sshole", which is the most honest vendor-adjacent naming we have had all year. On affected servers running the standard openssh-server package, an attacker who can reach the port, knows an account name, and types a password between 257 and 1,024 bytes long gets in — to accounts configured to block password authentication, including key-only accounts. No credential required. The credential is the length.
The reach is the part worth your morning. This is not an Alpine story, whatever the first headlines said: it is a musl story, which means Alpine, OpenWrt, Buildroot, Yocto and a great many Docker images, and it has been sitting there since 2016. Those are precisely the fleets that never receive a distro-style notice, because nobody signed up for one, because the thing is a router in a cupboard or a base image three Dockerfiles deep in a build that last had a human look at it when the person who wrote it still worked here.
The fix is OpenSSH 10.6p2, or set PasswordAuthentication no and mean it. There is a deeper point and it is almost theological: "this account has no password" is a statement about the world, and a statement about the world is only a control once somebody has tried to falsify it. For ten years nobody tried a long enough string. Go and try a long enough string.
Why it mattersInventory everything running SSH on musl — Alpine containers, OpenWrt, Buildroot and Yocto images — patch to 10.6p2 or disable password auth outright, then test it with an oversized password rather than believing the config file.
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