CVE-2023-47641

CVE-2023-47641 is a low-severity vulnerability in Aiohttp with a CVSS 3.x base score of 3.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-444.

Key facts

Description

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Affected versions of aiohttp have a security vulnerability regarding the inconsistent interpretation of the http protocol. HTTP/1.1 is a persistent protocol, if both Content-Length(CL) and Transfer-Encoding(TE) header values are present it can lead to incorrect interpretation of two entities that parse the HTTP and we can poison other sockets with this incorrect interpretation. A possible Proof-of-Concept (POC) would be a configuration with a reverse proxy(frontend) that accepts both CL and TE headers and aiohttp as backend. As aiohttp parses anything with chunked, we can pass a chunked123 as TE, the frontend entity will ignore this header and will parse Content-Length. The impact of this vulnerability is that it is possible to bypass any proxy rule, poisoning sockets to other users like passing Authentication Headers, also if it is present an Open Redirect an attacker could combine it to redirect random users to another website and log the request. This vulnerability has been addressed in release 3.8.0 of aiohttp. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Frequently asked questions

What is CVE-2023-47641?
aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Affected versions of aiohttp have a security vulnerability regarding the inconsistent interpretation of the http protocol. HTTP/1.1 is a persistent protocol, if both Content-Length(CL) and Transfer-Encoding(TE) header values are present it can lead to incorrect interpretation of two entities that parse the HTTP and we can poison other sockets with this incorrect interpretation. A possible Proof-of-Concept (POC) would be a configuration with a reverse proxy(frontend) that accepts both CL and TE headers and aiohttp as backend. As aiohttp parses anything with chunked, we can pass a chunked123 as TE, the frontend entity will ignore this header and will parse Content-Length. The impact of this vulnerability is that it is possible to bypass any proxy rule, poisoning sockets to other users like passing Authentication Headers, also if it is present an Open Redirect an attacker could combine it to redirect random users to another website and log the request. This vulnerability has been addressed in release 3.8.0 of aiohttp. Users are advised to upgrade. There are no known workarounds for this vulnerability.
How severe is CVE-2023-47641?
CVE-2023-47641 has a CVSS 3.x base score of 3.4, rated low severity. It is exploitable over network with high attack complexity, requires no privileges and user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2023-47641 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (53rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2023-47641?
CVE-2023-47641 affects Aiohttp. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2023-47641?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2023-47641 published?
CVE-2023-47641 was published on 2023-11-14 and last updated on 2026-06-17.

References

Affected products (1)

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