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 >
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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

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Vendor description:
-------------------


Vulnerability overview/description:
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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:
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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:
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Http://www.hik-connect.com/ (and all geographically distributed servers)


Vendor contact timeline:
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2018-04-21: Sent initial report to Hikvision