asyncssh@1.9.0 vulnerabilities

Affected versions of this package are vulnerable to Authentication Bypass by Capture-replay during the establishment of the secure channel. An attacker can manipulate handshake sequence numbers to delete messages sent immediately after the channel is established.

Note:

1. Sequence numbers are only validated once the channel is established and arbitrary messages are allowed during the handshake, allowing them to manipulate the sequence numbers.

2. The potential consequences of the general Terrapin attack are dependent on the messages exchanged after the handshake concludes. If you are using a custom SSH service and do not resort to the authentication protocol, you should check that dropping the first few messages of a connection does not yield security risks.

Impact:

While cryptographically novel, there is no discernable impact on the integrity of SSH traffic beyond giving the attacker the ability to delete the message that enables some features related to keystroke timing obfuscation. To successfully carry out the exploitation, the connection needs to be protected using either the ChaCha20-Poly1305 or CBC with Encrypt-then-MAC encryption methods. The attacker must also be able to intercept and modify the connection's traffic.

Upgrade asyncssh to version 2.14.2 or higher.

Affected versions of this package are vulnerable to Exposure of Private Personal Information to an Unauthorized Actor during the SSH client session. This allows the attacker to control the remote end of the SSH session, receiving all keyboard input by the user, completely controlling the terminal output of the user's session, sending and receiving data to/from forwarded network ports, and creating signatures with a forwarded SSH Agent, if any.

Upgrade asyncssh to version 2.14.1 or higher.

Affected versions of this package are vulnerable to Improper Validation of Integrity Check Value. An attacker can exploit an implementation flaw in the AsyncSSH implementation to inject an extension info message chosen by the attacker and delete the original extension info message, effectively replacing it.

Note: AsyncSSH supports the server-sig-algs and global-requests-ok extensions. Hence, the attacker can downgrade the algorithm used for client authentication by meddling with the value of server-sig-algs.

Upgrade asyncssh to version 2.14.1 or higher.

Affected versions of this package are vulnerable to Denial of Service (DoS). It does not limit line length when the editor is in use.

Upgrade asyncssh to version 2.5.0 or higher.

asyncssh is a Python package which provides an asynchronous client and server implementation of the SSHv2 protocol on top of the Python 3.4+ asyncio framework.

Affected versions of this package are vulnerable to Authentication Bypass. It does not properly check whether authentication is completed before processing other requests. A customized SSH client can simply skip the authentication step.

Upgrade asyncssh to version 1.12.1 or higher.