AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.3, an out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response. An attacker controlled server, or possibly an accidental response, could trigger a DoS in the client.
The vulnerable path was error message construction in aiohttp/_http_parser.pyx, where an llhttp error-position pointer was used to build a snippet for malformed chunked responses and malformed request or response bytes at the buffer end. This issue is fixed in version 3.14.3.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
References 4
https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c…
security-advisories@github.com
https://github.com/aio-libs/aiohttp/pull/13223
security-advisories@github.com
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3
security-advisories@github.com
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273
security-advisories@github.com