API: Bug in method auth.validatePhone

Disclosed: 2015-07-17 22:20:17 By vladislav805 To vkcom
Unknown
Vulnerability Details
The bug is that auth.validatePhone does not validate the parameter "sid". In theory he should be in the format "2fa_$userId_$appId_$hash", but to get the correct result (send SMS/make call) enough only "2fa_$userId_$anyText". For example, these requests will send a SMS: https://api.vk.com/method/auth.validatePhone?sid=2fa_23048942_lolka https://api.vk.com/method/auth.validatePhone?sid=2fa_66748_блаблабла It turns out that with this endlessly send SMS with the activation code, and to call if the request to add voice=1: https://api.vk.com/method/auth.validatePhone?sid=2fa_66748_блаблабла&voice=1 There is also another bug. SMS and calls will be carried out in any case, even if the user has disabled two-factor authentication. // I don't know, are you interested. But there is a bug - I reported.
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Report Stats
  • Report ID: 64963
  • State: Closed
  • Substate: resolved
  • Upvotes: 2
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