CVE-2024-0243: langchain Server-Side Request Forgery vulnerability

With the following crawler configuration:

from bs4 import BeautifulSoup as Soup

url = "https://example.com"
loader = RecursiveUrlLoader(
    url=url, max_depth=2, extractor=lambda x: Soup(x, "html.parser").text
)
docs = loader.load()

An attacker in control of the contents of https://example.com could place a malicious HTML file in there with links like “https://example.completely.different/my_file.html" and the crawler would proceed to download that file as well even though prevent_outside=True.