Possible security vulnerability: Increase firebase/php-jwt > 6.0

Thank you for the report.
I discussed this with the security team, including pwolanin who confronted the same issue for https://www.drupal.org/project/jwt

tl;dr: the CVE for PHP-JWT does not affect Salesforce Suite

The vulnerability depends on using a keychain (multiple keys in an array or \ArrayAccess interface object) as the 2nd argument passed into JWT::decode(), and on having multiple algorithms passed in the array as the 3rd argument. In addition the keychain must have a mix of algorithm types such as both RS256 and HS256.

salesforce_jwt only calls JWT::encode($token, $key, 'RS256') and never JWT::decode() so it cannot possibly be vulnerable to the key confusion issue.

See more info on the https://www.drupal.org/project/jwt project page.

Also, in the future, please follow security issue reporting protocol to report any potential security vulnerabilities.

Note that version 5.x of firebase/jwt no longer seems supported, since the security vulnerability was addressed only in the 6.x branch of that project. However, it seems there's nothing preventing users of this module from updating to the 6.x branch. It's true that the composer.json file in the salesforce_jwt submodule lists 5.x as required, composer doesn't look at the composer.json files of submodules when resolving dependency requirements.

I think the Salesforce module should update to test and declare support of the 6.x branch of firebase/jwt, but from what I can tell that package's API is limited to one method call to encode a JWT. There don't appear to be any breaking changes from the 5.x > 6.x branch that would impact the way this module uses that API call.

Also, in case anyone did not realize, now that the roave/security-advisories package is aware of this, it blocks a composer update if the installed firebase/php-jwt package is 5.x.

I didn't have any problems manually requiring firebase/php-jwt:6.0 and it looks like the salesforce:5.0.x-dev version has an updated composer.json to support 5.0 or 6.0 so I figure this issue will get resolved eventually.