There is a full write up of this bug here: https://medium.com/@evstykas/hackvision-8f50924e56d <https://medium.com/@evstykas/hackvision-8f50924e56d> Vulnerability Security Advisory < 20180424 > ======================================================================= title: No validation on cookie values product: hik-connect.com and ezvizlife.com vulnerable version: latest fixed version: fixed CVE number: - impact: critical found: 2018-04-19 by: Vangelis Stykas & George Lavdanis ======================================================================= Vendor description: ------------------- Vulnerability overview/description: ----------------------------------- 1) No validation on cookie values Both cloud services (hik-connect.com and ezvizlife.com) rely on cookie value AS_UserID to authenticate the user.Directly changing the value to another valid User id will result in hijacking that user session and be access its cameras/DVRS and change its password and/or email and phone.As the user id is not an incremental number but a hash we will need a way of finding out valid User ids. In order to do that we can use the https://xxx.ezvizlife.com/friend/queryByMobile.json or endpoint AFTER making that user a friend and get his userId. That endpoints has a GET parameter (mobile) that will check for a user with username, email or phone number. After that changing the cookie value to his user id will result in having us logged in as that user. Proof of concept: ----------------- 1) No validation on cookie values: ### Details * Attack Vector: HTTP GET * Prerequisites: None * CWE: CWE-784: Reliance on Cookies without Validation and Integrity Checking in a Security Decision * Technical Impact: Login as any user with no password required * Vulnerable query URL: / * Vulnerable Cookie parameter: AS_UserId Vulnerable / tested versions: ----------------------------- Http://www.hik-connect.com/ (and all geographically distributed servers) Vendor contact timeline: ------------------------ 2018-04-21: Sent initial report to Hikvision