CVE-2020-8164: High severity ruby on rails vulnerability

There is a strong parameters bypass vector in ActionPack.

Versions Affected: rails <= 6.0.3 Not affected: rails < 5.0.0 Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1

Impact ------ In some cases user supplied information can be inadvertently leaked from Strong Parameters. Specifically the return value of each, or eachvalue, or eachpair will return the underlying "untrusted" hash of data that was read from the parameters. Applications that use this return value may be inadvertently use untrusted user input.

Impacted code will look something like this:

def update # Attacker has included the parameter: { isadmin: true } User.update(cleanupparams) end

def cleanupparams params.each { |k, v| SomeModel.check(v) if k == :name } end

Note the mistaken use of each in the cleanupparams method in the above example.

Workarounds ----------- Do not use the return values of each, eachvalue, or eachpair in your application.