Critical Vulnerability in Python Package 'python-aiosmtpd' - Potential Man-in-the-Middle Attack
Summary
UBUNTU-CVE-2024-34083: aiosmptd is a reimplementation of the Python stdlib smtpd.py based on asyncio. Affects python-aiosmtpd versions 1.1-3 – 1.1-5. No fix is published. How to fix ↓
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Background
The 'python-aiosmtpd' package is a reimplementation of the Python standard library's smtpd.py, designed to provide asynchronous SMTP server capabilities using asyncio. It is widely used for handling email protocols in Python applications. However, prior to version 1.4.6, this package was vulnerable to a significant security flaw that allowed unencrypted commands to be accepted after a STARTTLS command, potentially exposing sensitive data to attackers.
Vulnerability Detail
The vulnerability identified as CVE-2024-34083 arises from the handling of commands in the 'python-aiosmtpd' package. Specifically, servers based on this package accepted additional unencrypted commands after the STARTTLS command, treating them as if they originated from within an encrypted connection. This flaw could be exploited by a man-in-the-middle attack, allowing attackers to intercept and manipulate communications. The vulnerability has a CVSS score of 5.4, indicating a medium severity level.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
As a temporary workaround, it is recommended to disable the use of STARTTLS in configurations until the package can be updated. This can be done by modifying the server settings to avoid initiating STARTTLS, thus preventing the acceptance of unencrypted commands.
Conclusion
The vulnerability in the 'python-aiosmtpd' package poses a significant risk due to the potential for man-in-the-middle attacks. It is crucial for users to update to version 1.4.6 or later to mitigate this risk. Additionally, temporary workarounds can be employed until the update is applied.
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FAQ
CVE-2024-34083 is a vulnerability in the 'python-aiosmtpd' package that allows unencrypted commands to be accepted after a STARTTLS command, posing a risk of man-in-the-middle attacks.
You can use the Vulert playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The vulnerability has a CVSS score of 5.4, indicating a medium severity level.
If immediate updates are not possible, consider disabling STARTTLS in your server configuration as a temporary workaround.
Vulert is a service that monitors and alerts for open-source vulnerabilities in software using a manifest file like package-lock.json. More information can be found at https://vulert.com.
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