CVE-2023-37276
MediumCVSS 5.3Exploitation Probability (EPSS)
Elevated risk69th percentile - higher than 69% of all known CVEs
Summary
A vulnerability in aiohttp (up to version 3.8.4) allows HTTP request smuggling attacks due to misinterpretation of HTTP header values. This affects users running aiohttp as an HTTP server.
Risk Assessment
Organizations using aiohttp as an HTTP server may be exposed to attacks that could lead to unauthorized access or data manipulation.
Recommendation
It is recommended to upgrade to version 3.8.5 or reinstall aiohttp with the llhttp parser disabled by setting the environment variable AIOHTTP_NO_EXTENSIONS=1.
Original NVD description (English source)
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. aiohttp v3.8.4 and earlier are bundled with llhttp v6.0.6. Vulnerable code is used by aiohttp for its HTTP request parser when available which is the default case when installing from a wheel. This vulnerability only affects users of aiohttp as an HTTP server (ie `aiohttp.Application`), you are not affected by this vulnerability if you are using aiohttp as an HTTP client library (ie `aiohttp.ClientSession`). Sending a crafted HTTP request will cause the server to misinterpret one of the HTTP header values leading to HTTP request smuggling. This issue has been addressed in version 3.8.5. Users are advised to upgrade. Users unable to upgrade can reinstall aiohttp using `AIOHTTP_NO_EXTENSIONS=1` as an environment variable to disable the llhttp HTTP request parser implementation. The pure Python implementation isn't vulnerable.