CVE-2024-23829 aiohttp's HTTP parser (the python one, not llhttp) still overly lenient about separators
Attackers can cause denial of service via unhandled exceptions or potentially bypass security controls through request smuggling due to lenient HTTP parsing.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-23829?
CVE-2024-23829 is a medium-severity vulnerability in Fedoraproject Fedora, published on 29 Jan 2024. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Security-sensitive parts of the Python HTTP parser retained minor differences in allowable character sets, that must trigger error handling to robustly match frame boundaries of proxies in order to protect against injection of additional requests. Additionally, validation could trigger exceptions that were not handled consistently with processing of other malformed input. Being more lenient than internet standards require could, depending on deployment environment, assist in request smuggling. The unhandled exception could cause excessive resource consumption on the application server and/or its logging facilities. This vulnerability exists due to an incomplete fix for CVE-2023-47627. Version 3.9.2 fixes this vulnerability.
Weakness: CWE-444
Which versions are affected by CVE-2024-23829?
3 open source packages ship an affected version, including aiohttp. It affects 2 products.
| Package | Affected | Fixed in |
|---|---|---|
aiohttp PyPI | All versions | 3.9.2 |
aiohttp PyPI | All versions | 3.9.2 |
aiohttp PyPI | All versions | 3.9.2 |
Products include Aiohttp Aiohttp, Fedoraproject Fedora.
How do I fix CVE-2024-23829?
Upgrade aiohttp to 3.9.2 or later.
Is CVE-2024-23829 being exploited?
There is no known exploitation of CVE-2024-23829 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
- CVE-2024-52303 aiohttp memory leak when middleware is enabled when requesting a resource with a non-allowed method
- CVE-2025-69223 AIOHTTP's HTTP Parser auto_decompress feature is vulnerable to zip bomb
- CVE-2024-30251 Denial of service when trying to parse malformed POST requests in aiohttp
- CVE-2023-49081 aiohttp's ClientSession is vulnerable to CRLF injection via version
- CVE-2026-22815 AIOHTTP: Uncapped memory usage possible through aiohttp allowing unlimited trailer headers
Sources
Also known as AZL-43774, AZL-45189, CLSA-2026-1768349585, DEBIAN-CVE-2024-23829, ECHO-e8ca-86bc-10b8, GHSA-8qpw-xqxj-h4r2 and 3 more.