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. 

[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?

---

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.