CVE-2018-7749: asyncssh - Incomplete Authentication Check
Summary
CVE-2018-7749: The SSH server implementation of AsyncSSH before 1.12.1 does not properly check whether authentication is completed before processing other requests. Affects asyncssh across 2 version ranges.
< 1.12.1
< c161e26cdc0d41b745b63d9f17b437f073bf7ba4
Fixed in c161e26cdc0d41b745b63d9f17b437f073bf7ba4. How to fix ↓
Also tracked for
- python-asyncssh · Debian:11
The same CVE-2018-7749 is tracked separately for each ecosystem and vendor. Its fix information is the same; the package and affected versions differ.
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Background
asyncssh is a Python library that provides an asynchronous SSH client and server implementation. It allows users to establish secure connections and perform SSH operations programmatically. The library is widely used in various Python applications for SSH communication.
Vulnerability Detail
The SSH server implementation of AsyncSSH before version 1.12.1 does not properly check whether authentication is completed before processing other requests. This flaw can be exploited by a customized SSH client to skip the authentication step altogether. As a result, unauthorized access to the SSH server may be granted without providing valid credentials. This vulnerability poses a significant security risk as it undermines the fundamental security mechanism of SSH authentication.
How To Fix
Latest published version: 2.24.1 as of 23 Oct 2026
pip install --upgrade "asyncssh==2.24.1"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
c161e26cdc0d41b745b63d9f17b437f073bf7ba4
This is the first release that contains the fix.
pip install --upgrade "asyncssh==c161e26cdc0d41b745b63d9f17b437f073bf7ba4"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There is no known workaround for this vulnerability. It is crucial to update to the fixed version of AsyncSSH to mitigate the risk of unauthorized access.
Conclusion
The vulnerability in AsyncSSH before version 1.12.1 allows unauthorized access to SSH servers by bypassing the authentication step. To mitigate this risk, it is crucial to update to the fixed version of AsyncSSH. For further assistance and support in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for asyncssh →
FAQ
AsyncSSH is a Python library that provides an asynchronous SSH client and server implementation. It allows secure communication over SSH protocol.
This vulnerability allows an attacker to bypass authentication and gain unauthorized access to an SSH server using a customized SSH client.
To fix this vulnerability, upgrade to AsyncSSH version 1.12.1 or later.
No, there is no known workaround for this vulnerability. Updating to the fixed version is the recommended solution.
You can find more information about this vulnerability in the official advisory: [link to advisory]
References
Related vulnerabilities
Recent vulnerabilities recorded for asyncssh.
