Impact
This vulnerability impacts applications using the omniauth-apple strategy of OmniAuth and using the info.email field of OmniAuth's Auth Hash Schema for any kind of identification. The value of this field may be set to any value of the attacker's choice including email addresses of other users.
For example, an application using omniauth-apple with the following code will be impacted:
def omniauth_callback
auth_hash = request.env['omniauth.auth']
@authenticated_user = User.find_by(email: auth_hash.info.email)
end
Applications not using info.email for identification but are instead using the uid field are not impacted in the same manner. Note, these applications may still be negatively affected if the value of info.email is being used for other purposes.
Patches
Applications using affected versions of omniauth-apple are advised to upgrade to omniauth-apple version 1.0.1 or later.
Workarounds
If unable to upgrade to a patched version, monkey patching OmniAuth::Strategies::Apple#email as follows is advised as a workaround:
module OmniAuth
module Strategies
class Apple
def email
id_info['email']
end
end
end
end
References
Commit with fix: b37d540
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26254
Impact
This vulnerability impacts applications using the omniauth-apple strategy of OmniAuth and using the
info.emailfield of OmniAuth's Auth Hash Schema for any kind of identification. The value of this field may be set to any value of the attacker's choice including email addresses of other users.For example, an application using omniauth-apple with the following code will be impacted:
Applications not using
info.emailfor identification but are instead using theuidfield are not impacted in the same manner. Note, these applications may still be negatively affected if the value ofinfo.emailis being used for other purposes.Patches
Applications using affected versions of omniauth-apple are advised to upgrade to omniauth-apple version 1.0.1 or later.
Workarounds
If unable to upgrade to a patched version, monkey patching
OmniAuth::Strategies::Apple#emailas follows is advised as a workaround:References
Commit with fix: b37d540
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-26254