Hono vulnerable to bypass of CSRF Middleware by a request without Content-Type header.

Vulnerability Description

Hono, a web framework, prior to version 4.6.5 is vulnerable to bypass of cross-site request forgery (CSRF) middleware by a request without Content-Type header. Although the CSRF middleware verifies the Content-Type Header, Hono always considers a request without a Content-Type header to be safe. This can allow an attacker to bypass CSRF protection implemented with Hono CSRF middleware. Version 4.6.5 fixes this issue.

References

• https://github.com/honojs/hono/security/advisories/GHSA-2234-fmw7-43wr
• https://github.com/honojs/hono/commit/aa50e0ab77b5af8c53c50fe3b271892f8eeeea82
• https://github.com/honojs/hono/blob/cebf4e87f3984a6a034e60a43f542b4c5225b668/src/middleware/csrf/index.ts#L76-L89