CVE-2024-42367

Path traversal vulnerability in aiohttp for compressed file variants.

• CVSS 4.8
• CWE-61
• Input Validation and Sanitization
• Remote

aiohttp is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.10.2, static routes which contain files with compressed variants (`.gz` or `.br` extension) are vulnerable to path traversal outside the root directory if those variants are symbolic links. The server protects static routes from path traversal outside the root directory when `follow_symlinks=False` (default). It does this by resolving the requested URL to an absolute path and then checking that path relative to the root. However, these checks are not performed when looking for compressed variants in the `FileResponse` class, and symbolic links are then automatically followed when performing the `Path.stat()` and `Path.open()` to send the file. Version 3.10.2 contains a patch for the issue.

CVE

CVE-2024-42367

CWE

CWE-61

CVSS base score

4.8

Published

2024-08-09

OWASP

A01 Broken Access Control

Orthogonal defect classification

Checking

Code defect classification

Incorrect Check

Category

Input Validation and Sanitization

Subcategory

Path Traversal

Accessibility scope

Remote

Impact

Unauthorized Access

Affected component

aiohttp

Fixed by upgrading

Yes

Solution

Upgrade to aiohttp version 3.10.2 or later.

from aiohttp import web

async def handle(request):
    return web.FileResponse(request.match_info['filename'])

app = web.Application()
app.router.add_get('/static/{filename:.*}', handle)

if __name__ == '__main__':
    web.run_app(app, port=8080)

from aiohttp import web
import os

async def handle(request):
    return web.FileResponse(request.match_info['filename'], follow_symlinks=False)

app = web.Application()
app.router.add_get('/static/{filename:.*}', handle)

if __name__ == '__main__':
    web.run_app(app, port=8080)

../../../../etc/passwd

@misc{vaitp:cve202442367,
  title        = {{Path traversal vulnerability in aiohttp for compressed file variants.}},
  author       = {Bogaerts, Fr\'ed\'eric and Ivaki, Naghmeh and Fonseca, Jos\'e},
  year         = {2024},
  note         = {VAITP Python Vulnerability Dataset, entry CVE-2024-42367},
  howpublished = {\url{https://netpack.pt/vaitp/vulnerability/CVE-2024-42367/}}
}