GHSA-5m98-qgg9-wh84

Source
https://github.com/advisories/GHSA-5m98-qgg9-wh84
Import Source
https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/05/GHSA-5m98-qgg9-wh84/GHSA-5m98-qgg9-wh84.json
Aliases
Published
2024-05-03T17:29:54Z
Modified
2024-05-03T18:02:59.170557Z
Summary
aiohttp vulnerable to Denial of Service when trying to parse malformed POST requests
Details

Summary

An attacker can send a specially crafted POST (multipart/form-data) request. When the aiohttp server processes it, the server will enter an infinite loop and be unable to process any further requests.

Impact

An attacker can stop the application from serving requests after sending a single request.

For anyone needing to patch older versions of aiohttp, the minimum diff needed to resolve the issue is (located in _read_chunk_from_length()):

diff --git a/aiohttp/multipart.py b/aiohttp/multipart.py
index 227be605c..71fc2654a 100644
--- a/aiohttp/multipart.py
+++ b/aiohttp/multipart.py
@@ -338,6 +338,8 @@ class BodyPartReader:
         assert self._length is not None, "Content-Length required for chunked read"
         chunk_size = min(size, self._length - self._read_bytes)
         chunk = await self._content.read(chunk_size)
+        if self._content.at_eof():
+            self._at_eof = True
         return chunk

     async def _read_chunk_from_stream(self, size: int) -> bytes:

This does however introduce some very minor issues with handling form data. So, if possible, it would be recommended to also backport the changes in: https://github.com/aio-libs/aiohttp/commit/cebe526b9c34dc3a3da9140409db63014bc4cf19 https://github.com/aio-libs/aiohttp/commit/7eecdff163ccf029fbb1ddc9de4169d4aaeb6597 https://github.com/aio-libs/aiohttp/commit/f21c6f2ca512a026ce7f0f6c6311f62d6a638866

References

Affected packages

PyPI / aiohttp

Package

Name
aiohttp

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0The exact introduced commit is unknown
Fixed
3.9.4

Affected versions

0.*

0.1
0.2
0.3
0.4
0.4.1
0.4.2
0.4.3
0.4.4
0.5.0
0.6.0
0.6.1
0.6.2
0.6.3
0.6.4
0.6.5
0.7.0
0.7.1
0.7.2
0.7.3
0.8.0
0.8.1
0.8.2
0.8.3
0.8.4
0.9.0
0.9.1
0.9.2
0.9.3
0.10.0
0.10.1
0.10.2
0.11.0
0.12.0
0.13.0
0.13.1
0.14.0
0.14.1
0.14.2
0.14.3
0.14.4
0.15.0
0.15.1
0.15.2
0.15.3
0.16.0
0.16.1
0.16.2
0.16.3
0.16.4
0.16.5
0.16.6
0.17.0
0.17.1
0.17.2
0.17.3
0.17.4
0.18.0
0.18.1
0.18.2
0.18.3
0.18.4
0.19.0
0.20.0
0.20.1
0.20.2
0.21.0
0.21.1
0.21.2
0.21.4
0.21.5
0.21.6
0.22.0a0
0.22.0b0
0.22.0b1
0.22.0b2
0.22.0b3
0.22.0b4
0.22.0b5
0.22.0b6
0.22.0
0.22.1
0.22.2
0.22.3
0.22.4
0.22.5

1.*

1.0.0
1.0.1
1.0.2
1.0.3
1.0.5
1.1.0
1.1.1
1.1.2
1.1.3
1.1.4
1.1.5
1.1.6
1.2.0
1.3.0
1.3.1
1.3.2
1.3.3
1.3.4
1.3.5

2.*

2.0.0rc1
2.0.0
2.0.1
2.0.2
2.0.3
2.0.4
2.0.5
2.0.6
2.0.7
2.1.0
2.2.0
2.2.1
2.2.2
2.2.3
2.2.4
2.2.5
2.3.0a1
2.3.0a2
2.3.0a3
2.3.0a4
2.3.0
2.3.1a1
2.3.1
2.3.2b2
2.3.2b3
2.3.2
2.3.3
2.3.4
2.3.5
2.3.6
2.3.7
2.3.8
2.3.9
2.3.10

3.*

3.0.0b0
3.0.0b1
3.0.0b2
3.0.0b3
3.0.0b4
3.0.0
3.0.1
3.0.2
3.0.3
3.0.4
3.0.5
3.0.6
3.0.7
3.0.8
3.0.9
3.1.0
3.1.1
3.1.2
3.1.3
3.2.0
3.2.1
3.3.0a0
3.3.0
3.3.1
3.3.2a0
3.3.2
3.4.0a0
3.4.0a3
3.4.0b1
3.4.0b2
3.4.0
3.4.1
3.4.2
3.4.3
3.4.4
3.5.0a1
3.5.0b1
3.5.0b2
3.5.0b3
3.5.0
3.5.1
3.5.2
3.5.3
3.5.4
3.6.0a0
3.6.0a1
3.6.0a2
3.6.0a3
3.6.0a4
3.6.0a5
3.6.0a6
3.6.0a7
3.6.0a8
3.6.0a9
3.6.0a11
3.6.0a12
3.6.0b0
3.6.0
3.6.1b3
3.6.1b4
3.6.1
3.6.2a0
3.6.2a1
3.6.2a2
3.6.2
3.6.3
3.7.0b0
3.7.0b1
3.7.0
3.7.1
3.7.2
3.7.3
3.7.4
3.7.4.post0
3.8.0a7
3.8.0b0
3.8.0
3.8.1
3.8.2
3.8.3
3.8.4
3.8.5
3.8.6
3.9.0b0
3.9.0b1
3.9.0rc0
3.9.0
3.9.1
3.9.2
3.9.3
3.9.4rc0