Untrusted users able to run pending migrations in production

How it was found

Untrusted users able to run pending migrations in production

There is a vulnerability in versions of Rails prior to 6.0.3.2 that allowed an untrusted user to run any pending migrations on a Rails app running in production.

This vulnerability has been assigned the CVE identifier CVE-2020-XXXX.

Versions Affected: 6.0.0 < rails < 6.0.3.2 Not affected: Applications with config.action_dispatch.show_exceptions = false (this is not a default setting in production) Fixed Versions: rails >= 6.0.3.2

Releases

The new release (6.0.3.2) is available in the regular locations.

Workarounds

Until such time as the patch can be applied, application developers should disable the ActionDispatch middleware in their production environment via a line such as this one in their config/environment/production.rb:

config.middleware.delete ActionDispatch::ActionableExceptions

Patches

As mentioned, we are releasing the following patch for the 6.0 release series:

• 0001-6.0.3.1-Only-allow-ActionableErrors-if-show_detailed_excepti.patch

Credits

This issue was discovered independently by Rafael França and Benoit Côté-Jodoin. The patch above was provided by Rafael.

Impact

Using this issue, an attacker would be able to execute any migrations that are pending for a Rails app running in production mode. It is important to note that an attacker is limited to running migrations the application developer has already defined in their application and ones that have not already ran.