MIUI Wifi Connection Message Vulnerability

[vuln@xxxxxxxxxxx]

MIUI Wifi Connection Message Vulnerability

I. Summary
Wifi Connection Message is written to a NFC tag, which can be touched by a NFC 
mobile phone for connecting wireless AP 

automatically. A logic flaw has been found in MIUI that is a Android ROM. The 
flaw can be used to turn on wifi, with the 

help of 
"wifihandover"(https://play.google.com/store/apps/details?id=net.endflow.apps.wifiho)
 or "NFC Tag 

Assistant"（http://app.mi.com/detail/43940）.
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II. Description
According to the NFC Wifi Connection Message Specification, construct a message 
as follow.
D2 17 45 61 70 70 6C 69 63 61 74 69 6F 6E 2F 76
6E 64 2E 77 66 61 2E 77 73 63 10 4A 00 01 10 10
0E 00 3C 10 26 00 01 01 10 45 00 04 55 43 41 53
10 03 00 02 00 20 10 0F 00 02 00 08 10 27 00 10
5B 0F A0 A8 11 2B 5B EF F0 C2 10 3E D6 91 5C B1
10 20 00 06 88 32 9B 57 F1 CC FF FF 00 01 02

Then write the message to NFC tag. For the reason MIUI 5.30（a Android 
ROM）don't process wifi message，"wifihandover" or 

"NFC Tag Assistant" should be installed in the tested phone. Touch the NFC tag 
with a smart phone with Samsung GT-I9300

(installed with MIUI 5.30， an Android ROM), wifi will be turned on 
automatically, regardless of whether wifi connection 

succeeds or not.
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III. Impact
This bug cause wifi connection turned on automatically
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IV. Affected
MIUI  4.1.17/5.30 
other versions we don't test.
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V. Solution
modify the source codes about Wifi connection message processing strategy.