CVE-2021-32677: fedoraproject fedora Cross-Site Request Forgery (CSRF)

Vulnerability summary

CVE-2021-32677 is a high (CVSS 8.2) Cross-Site Request Forgery (CSRF) vulnerability in fedoraproject fedora. EPSS estimates a 0.72% chance of exploitation in the next 30 days, higher than 53.1% of scored vulnerabilities.

Timeline

1. 09-06-2021
   PublishedVulnerability first disclosed.
2. 03-08-2024
   Last modifiedVulnerability information updated.

Description

FastAPI is a web framework for building APIs with Python 3.6+ based on standard Python type hints. FastAPI versions lower than 0.65.2 that used cookies for authentication in path operations that received JSON payloads sent by browsers were vulnerable to a Cross-Site Request Forgery (CSRF) attack. In versions lower than 0.65.2, FastAPI would try to read the request payload as JSON even if the content-type header sent was not set to application/json or a compatible JSON media type (e.g. application/geo+json). A request with a content type of text/plain containing JSON data would be accepted and the JSON data would be extracted. Requests with content type text/plain are exempt from CORS preflights, for being considered Simple requests. The browser will execute them right away including cookies, and the text content could be a JSON string that would be parsed and accepted by the FastAPI application. This is fixed in FastAPI 0.65.2. The request data is now parsed as JSON only if the content-type header is application/json or another JSON compatible media type like application/geo+json. It's best to upgrade to the latest FastAPI, but if updating is not possible then a middleware or a dependency that checks the content-type header and aborts the request if it is not application/json or another JSON compatible content type can act as a mitigating workaround.

• CWE-352Cross-Site Request Forgery (CSRF)The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.