CVE-2024-53981
Denial of service (DoS) via deformation `multipart/form-data` boundary
Impact
### Summary When parsing form data, `python-multipart` skips line breaks (CR `\r` or LF `\n`) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs. An attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS). ### Impact Applications that use `python-multipart` to parse form data (or use frameworks that do so) are affected. ### Original Report This security issue was reported by: - GitHub security advisory in Starlette on October 30 by @Startr4ck - Email to `python-multipart` maintainer on October 3 by @mnqazi
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| pip | python-multipart | < 0.0.18 | 0.0.18 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/Kludex/python-multipart/commit/c4fe4d3cebc08c660e57dd709af1ffa7059b3177
- https://github.com/Kludex/python-multipart/security/advisories/GHSA-59g5-xgcq-4qw3
- https://github.com/advisories/GHSA-59g5-xgcq-4qw3
- https://nvd.nist.gov/vuln/detail/CVE-2024-53981