Skip to main content

Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') in aiohttp

CVE-2025-53643

  • aiohttp
Low
1.7/10

Summary

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. If a pure Python version of aiohttp is installed (i.e., without the usual C extensions) or `AIOHTTP_NO_EXTENSIONS` is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. This issue affects versions through 3.12.13 and 4.0.0a0 through 4.0.0a1.

  • LOW
  • NETWORK
  • HIGH
  • UNCHANGED
  • NONE
  • NONE
  • NONE
  • NONE

CWE-444 - HTTP Request Smuggling

Entities such as web servers, web caching proxies, and application firewalls could parse HTTP requests differently. When there are two or more such entities in the path of an HTTP request, an attacker can send a specially crafted HTTP request that is seen as two different sets of requests by the attacked devices, allowing the attacker to smuggle a request into one device without the other device being aware of it. Such a vulnerability can prove devastating, for it enables further attacks on the application, like web cache poisoning, session hijacking, cross-site scripting, security bypassing, and sensitive information exposure.

References

Advisory Timeline

  • Published