asyncssh 1.2.1 vulnerabilities

Known vulnerabilities in the asyncssh package. This does not include vulnerabilities belonging to this package’s dependencies.

Vulnerability	Vulnerable Version
M Authentication Bypass by Capture-replay 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: 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. 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. How to fix Authentication Bypass by Capture-replay? Upgrade `asyncssh` to version 2.14.2 or higher.	[,2.14.2)
H Exposure of Private Personal Information to an Unauthorized Actor 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. How to fix Exposure of Private Personal Information to an Unauthorized Actor? Upgrade `asyncssh` to version 2.14.1 or higher.	[,2.14.1)
M Improper Validation of Integrity Check Value 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`. How to fix Improper Validation of Integrity Check Value? Upgrade `asyncssh` to version 2.14.1 or higher.	[,2.14.1)
H Denial of Service (DoS) Affected versions of this package are vulnerable to Denial of Service (DoS). It does not limit line length when the editor is in use. How to fix Denial of Service (DoS)? Upgrade `asyncssh` to version 2.5.0 or higher.	[,2.5.0)
C Authentication Bypass 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. How to fix Authentication Bypass? Upgrade `asyncssh` to version 1.12.1 or higher.	[,1.12.1)

Vulnerability

Vulnerable Version

Authentication Bypass by Capture-replay

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:

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.
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.

How to fix Authentication Bypass by Capture-replay?

Upgrade asyncssh to version 2.14.2 or higher.

[,2.14.2)

Exposure of Private Personal Information to an Unauthorized Actor

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.

How to fix Exposure of Private Personal Information to an Unauthorized Actor?

Upgrade asyncssh to version 2.14.1 or higher.

[,2.14.1)

Improper Validation of Integrity Check Value

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.

How to fix Improper Validation of Integrity Check Value?

Upgrade asyncssh to version 2.14.1 or higher.

[,2.14.1)

Denial of Service (DoS)

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

How to fix Denial of Service (DoS)?

Upgrade asyncssh to version 2.5.0 or higher.

[,2.5.0)

Authentication Bypass

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.

How to fix Authentication Bypass?

Upgrade asyncssh to version 1.12.1 or higher.

[,1.12.1)

asyncssh@1.2.1 vulnerabilities

AsyncSSH: Asynchronous SSHv2 client and server library

latest version

latest non vulnerable version

first published

latest version published

licenses detected

Direct Vulnerabilities

How to fix?