AsyncSSH is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python asyncio framework. Prior to 2.23.0, AsyncSSH expands the OpenSSH-compatible AuthorizedKeysFile %u token in asyncssh/config.py, asyncssh/connection.py, asyncssh/auth_keys.py, and asyncssh/misc.py with the raw SSH username during pre-authentication server config reload, allowing a server configured with AuthorizedKeysFile authorized_keys/%u to read an authorized-keys file outside the intended directory when the SSH username contains /, , or .. path traversal segments and authenticate with an attacker-selected key file. This issue is fixed in version 2.23.0.
1.2.0-11.2.1-11.3.0-11.12.2-11.12.2-1ubuntu0.11.12.2-1ubuntu0.2Exploitability
AV:NAC:LAT:PPR:NUI:NVulnerable System
VC:NVI:HVA:NSubsequent System
SC:NSI:NSA:NCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N