Request Smuggling Vulnerability in AIOHTTP Package
Summary
CVE-2025-53643: AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Affects python-aiohttp versions < e8d774f635dc6d1cd3174d0e38891da5de0e2b6a. No fix is published. How to fix ↓
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Background
AIOHTTP is an asynchronous HTTP client/server framework designed for Python's asyncio library. It allows developers to build web applications and services that can handle multiple requests concurrently. AIOHTTP is known for its flexibility and performance, making it a popular choice among Python developers. However, prior to version 3.12.14, AIOHTTP had a vulnerability related to the parsing of trailer sections in HTTP requests, which could lead to request smuggling attacks.
Vulnerability Detail
The vulnerability arises from the Python parser in AIOHTTP not properly parsing the trailer sections of HTTP requests. This oversight allows attackers to potentially execute request smuggling attacks, which can bypass firewalls or proxy protections. If a pure Python version of AIOHTTP is installed, or if the AIOHTTP_NO_EXTENSIONS option is enabled, the risk of exploitation increases significantly. The vulnerability is identified as CVE-2025-53643 and affects all versions prior to 3.12.14.
How To Fix
No fixed version is published for this vulnerability.
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Workaround
If immediate updating is not feasible, consider disabling the use of pure Python versions of AIOHTTP or ensuring that AIOHTTP_NO_EXTENSIONS is not enabled. Additionally, implementing strict input validation and monitoring network traffic for unusual patterns can help mitigate the risk.
Conclusion
The AIOHTTP package has a critical vulnerability that could allow request smuggling attacks, affecting applications using versions prior to 3.12.14. It is crucial to update to the patched version to mitigate risks. For those unable to update immediately, implementing workarounds and monitoring can help reduce exposure.
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FAQ
Request smuggling is a technique used by attackers to send malicious requests that can bypass security measures, allowing them to manipulate server behavior or access unauthorized resources.
You can check if your application is affected by using Vulert, which monitors and alerts for open-source vulnerabilities in real-time. Visit the Vulert playground at Vulert Scanner to analyze your manifest file.
If exploited, this vulnerability can allow attackers to bypass firewalls or proxy protections, potentially leading to unauthorized access or data breaches.
Yes, you can disable the use of pure Python versions of AIOHTTP or ensure that AIOHTTP_NO_EXTENSIONS is not enabled. Additionally, implementing strict input validation can help reduce risk.
If immediate updates are not possible, consider applying workarounds such as disabling vulnerable features and enhancing monitoring of your application for suspicious activities.
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