Threat log spammed with "Non-RFC Compliant DNS Traffic on Port 53/5353"

[Maxstr]

A couple days ago, the threatvault added threat id 56505, and since then our threat log is getting spammed with the vulnerability type Non-RFC Compliant DNS Traffic on Port 53/5353 (informational). We use dnscrypt, and every single DNS request is now showing up in the threat log. First of all, is this a false positive? And if so, how do I prevent this from inundating my logs?

[BPry · Accepted solution]

@Maxstr,

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@Maxstr wrote:

First of all, is this a false positive? And if so, how do I prevent this from inundating my logs?

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No, it's not a false positive; it also isn't unexpected if you are utilizing dnscrypt. DNSCrypt is not RFC compliant, hence you are hitting a signature that makes perfect sense. If you don't want it to keep showing up in your logs, you'll need to make an exception for 56505 on your Vulnerability profile and set it to allow. 

[felcor]

Helo All,

In my case I dont have DNSDecry and I see  threat id 56112 .

It is possible I consider a false positive ?

[MP18]

@felcor 

It is not false positive. It is information message only.

https://threatvault.paloaltonetworks.com/?query=56505

Regards

[mss-ops]

Name: Non-RFC Compliant DNS Traffic on Port 53/5353

56505

What is the solution for this, and what RFC standard it is not cpmpliant?