KAKAO TALK APP issue

[weezy]

Hi All,

Does anyone here encountered an issue on kakao talk app? A south Korean messaging app.

We have south korean users on our malaysia site that uses this app. When the user tries to login using their own hotspot they can connect without any issues, but when user is connected on our wifi, the user tries to login and was getting an error 50101, LL 

This is working since last year and the user complain it suddenly stop.

1. we already allowed the kakao talk app on our allowed app list.

2. This is the list of their public IP info AS9764 Kakao Corp details - IPinfo.io

This is the list of public IP's of kakao talk that I allowed on our PA 850 

203.217.230.241
203.217.236.8
203.133.166.18
203.217.238.9
203.133.167.14
203.217.239.58
113.29.190.178
113.29.189.165
203.133.172.4
203.217.226.4
203.217.231.74
113.29.191.220
203.133.165.241
211.183.219.26
113.29.179.43
211.183.218.4
203.133.160.220 

3. When I check the policy the hit counts I'm seeing the kakao talk app file transfer

4. The system admins had allowed this app as well on the windows laptop so the user should be able to use it without any issues.

5. I ask her to reach out to kakao support team to ask what is their public IP and the Kakao support told her that they cannot share their public IP details

This is the error they are getting and also the solution that server team suggested to put the installer on windows drive then install it, still don't work. The Local I.T installed as well the latest ver and reinstalled it still don't work.

All the troubleshooting steps and the full details about the APP are mentioned.

[BPry]

@weezy,

I have no experience with this application, but it sounds like something on your network is blocking the required application traffic. General questions:

• Do you decrypt traffic?
• Have you attempted to allow all traffic externally on a test client and see if the application works if it has an open security rulebase entry temporarily?
• If that doesn't work and you are decrypting traffic; attempt the same thing but this time adding a decryption exclusion.

Some applications will utilize certificate pinning and you simply can't decrypt them and expect the application to actually work. It could be that KakaoTalk has implemented certificate pinning in their application and you getting in the way of that is breaking the application. You would need to determine if the user's ability to utilize this application when on your network justifies an exclusion.

Assuming that you aren't decrypting traffic, then you are likely not fully accounting for all necessary network traffic. You will need to utilize a test endpoint and actually identify all requirements to build out the policy needed to facilitate allowing the network traffic. If you're limiting the application to IP addresses assigned to the company it is likely that you are blocking some of the application traffic that just doesn't go to directly allocated addresses. 

[weezy]

Hi ,

We don't decrypt. I created a specific security policy that will allow the IP addresses and the application. I did see a hit count but it doesn't see the apps.