@keystone-6/core's NODE_ENV defaults to development with esbuild

Impact

@keystone-6/[email protected] || 3.0.1 users that use NODE_ENV in their own code (not dependencies) to trigger security-sensitive functionality in a production build are vulnerable to NODE_ENV being inlined to "development" for user code.

If your dependencies use NODE_ENV to trigger particular behaviours (optimisations, security or otherwise), they should still respect your environment’s configured NODE_ENV variable and thereby be unaffected.

If you do not use NODE_ENV in your own code to trigger security-sensitive functionality, you are not impacted by this vulnerability.
An example of code that would be affected, might be the following:

if (process.env.NODE_ENV !== 'production') {
  // this code would unintentionally run in your production builds
}

Technical Description

The problem comes from esbuild defaulting NODE_ENV to "development" when a platform configuration is undefined.
You can read about why esbuild has that behaviour in their documentation, but the result for Keystone users is that user Typescript was compiled, and had inlined NODE_ENV to the constant "development".

Your application’s dependencies, as found in node_modules (including @keystone-6/core), are typically not compiled as part of this process, and thus should be unaffected. Therefore any libraries that used NODE_ENV to trigger particular behaviours (optimisations, security or otherwise) should still respect your environment’s NODE_ENV.
We have tested this assumption by verifying that NODE_ENV=production yarn keystone start still uses secure cookies when using statelessSessions.

Thereby, the severity of this vulnerability is dependent on what functionality users conditionally triggered, in their own code, depending on the expectation that NODE_ENV would be correctly configured in their application. In accordance with Common Vulnerability Scoring System 2.3.3. Assume Vulnerable Configurations, this security advisory assumes vulnerable configurations and is thus marked as critical, but you should evaluate the true security impact for your application to determine a relevant score.

Patches

This vulnerability has been fixed in @keystone-6/[email protected], thanks to @mmachatschek in https://github.com/keystonejs/keystone/pull/8031/.
We have added regression tests for this vulnerability in https://github.com/keystonejs/keystone/pull/8063.

Workarounds

If you cannot upgrade your @keystone-6/core version for any reason, your best alternative is to remove any code that uses NODE_ENV in a way that may reasonably impact your application security.

References

• https://esbuild.github.io/api/#platform
• https://github.com/keystonejs/keystone/pull/8031
• https://github.com/keystonejs/keystone/pull/8063

For more information

Thanks to Austin Burdine for reporting this problem as a potential security vulnerability.

If you have any questions around this security advisory, please don’t hesitate to contact us at [email protected], or open an issue on GitHub.

If you have a security flaw to report for any software in this repository, please see our SECURITY policy.