Meet *sshole, the vulnerability that lets hackers SSH into Linux devices
Certain configurations of Alpine are affected. Other distros may be as well.
TL;DR
- A vulnerability named *sshole allows passwordless SSH login on devices using specific configurations of Alpine Linux.
- The vulnerability requires OpenSSH, musl, password hashes using SHA256 or SHA512, and a passwordless account configured with a '*' in the /etc/shadow file.
- Attackers can exploit this by entering over 256 characters in the password field for passwordless accounts.
- Alpine Linux, widely used in embedded devices and containers, and OpenSSH have released patches.
- Other Linux distributions using musl and OpenSSH may also be affected.
- While root accounts with default settings are safe, accounts with sudo or doas rights can still escalate to root.