• Rémy Coutable's avatar
    Merge branch 'fix/2fa-authentication-spoofing' into 'master' · ea1b80ae
    Rémy Coutable authored
    Fix 2FA authentication spoofing
    
    ## Summary
    
    This is security fix for vulnerability described at
    https://gitlab.com/gitlab-org/gitlab-ce/issues/14900.
    
    Attacker was able to bypass password authentication of users that have 2FA enabled, and consequently sign is as a different user, without knowing his password, if he managed to guess 2FA One Time Password for that user.
    
    It was also possible to enumerate users and check if they have 2FA enabled, because GitLab responded with different error for each case.
    
    ## Fix
    
    This MR attempts to change default user search scope if `otp_user_id` session variable has been set. If it is present, it means that user has 2FA enabled, and has already been verified with login and password. In this case we should look for user with `otp_user_id` first, before picking it up by `login`.
    
    Both, 2FA authentication spoofing and 2FA discovery have been covered by specs.
    
    ## Further work
    
    Current 2FA code is a bit tricky, so it probably needs some refactoring.
    
    See merge request !1947
    Signed-off-by: default avatarRémy Coutable <remy@rymai.me>
    ea1b80ae
sessions_controller.rb 4.06 KB