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Zoom IP block is blacklisted

bro-tech
Listener

The Zoom block 170.114.0.0/16 has recently been blacklisted and is getting blocked by client firewalls that use dynamic malicious lists.

 

I checked this on Spamhaus and it shows up on their PBL as well.

 

Has this not been reported yet?

5 REPLIES 5

ryanty
Listener

Still being blocked.  Any remedy Zoom?

kelmcbri
Listener

Any address on the SpamHaus PBL list should be blocked from unauthenticated SMTP traffic. All other traffic is not included in the PBL.  If the address showed up on the SpamHaus DROP list, it should be treated as malicious and all traffic dropped.  170.114.0.0/16 is only showing on the SpamHaus PBL list so Zoom traffic can be safely allowed. 

-N-A-
Listener

We also use Spamhaus DROP and EDROP lists in our firewalls, and get complaints from users who can't connect to Zoom meetings because of that.
The security policy blocks any traffic to/from any IP listed. No exceptions.

dh23
Listener

Running into this same issue as well, please advise. 

kelmcbri
Listener

Zoom worked with SpamHaus and had 170.114.0.0/16 (and others) delisted yesterday from the SpamHaus PBL list. I'm not aware of any Zoom IPs on the DROP or eDROP lists. Your Zoom clients should be operating properly now. If you are still experiencing trouble, you may want to have your firewall team reset sessions to get the latest SpamHaus list.  I believe the longterm answer is to not filter ALL traffic based on the SpamHaus PBL list - this list is only meant for filtering unauthenticated SMTP (email) traffic.  The SpamHaus DROP list is for malicious IPs where all traffic should be dropped.