CVE-2024-47874 – starlette

Package

Manager: pip
Name: starlette
Vulnerable Version: >=0 <0.40.0

Severity

Level: High

CVSS v3.1: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:N

CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS: 0.00074 pctl0.22976

Details

Starlette Denial of service (DoS) via multipart/form-data ### Summary Starlette treats `multipart/form-data` parts without a `filename` as text form fields and buffers those in byte strings with no size limit. This allows an attacker to upload arbitrary large form fields and cause Starlette to both slow down significantly due to excessive memory allocations and copy operations, and also consume more and more memory until the server starts swapping and grinds to a halt, or the OS terminates the server process with an OOM error. Uploading multiple such requests in parallel may be enough to render a service practically unusable, even if reasonable request size limits are enforced by a reverse proxy in front of Starlette. ### PoC ```python from starlette.applications import Starlette from starlette.routing import Route async def poc(request): async with request.form(): pass app = Starlette(routes=[ Route('/', poc, methods=["POST"]), ]) ``` ```sh curl http://localhost:8000 -F 'big=</dev/urandom' ``` ### Impact This Denial of service (DoS) vulnerability affects all applications built with Starlette (or FastAPI) accepting form requests.

Metadata

Created: 2024-10-15T18:12:57Z
Modified: 2024-10-15T19:56:06Z
Source: https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/10/GHSA-f96h-pmfr-66vw/GHSA-f96h-pmfr-66vw.json
CWE IDs: ["CWE-770"]
Alternative ID: GHSA-f96h-pmfr-66vw
Finding: F002
Auto approve: 1