I am using my own device on my college's Wi-Fi. I've heard that many pieces of information about my device such as my OS version is sent through a browser such as Google Chrome. But how can he obtain my serial number if he wants?
The Wi-Fi admin can only get your MAC Address of your device.
He cannot get the IMEI number, unless he make you install some software or App on you device.
He also gets your OS version and browser details is via the request Headers of browsers.
Here is a sample. You can see the
User-Agent contains the info of your OS.
In my case
Windows NT 6.1 and browser information
POST /posts/validate-body HTTP/1.1 Host: security.stackexchange.com User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0 Accept: */* Accept-Language: en-US,en;q=0.5 Accept-Encoding: gzip, deflate DNT: 1 Content-Type: application/x-www-form-urlencoded; charset=UTF-8 X-Requested-With: XMLHttpRequest Referer: http://security.stackexchange.com/questions/135142/can-my-college-wi-fi-admin-obtain-the-serial-number-imei-of-my-device Content-Length: 177
You can spoof this Information as well using various methods.
The Above HTTP request headers can be read if you are browsing plaintext protocols like HTTP.
When a DHCP request is made the Hostname is sent as well.