[PATCH 3/3] Suricata: detect DNS events on port 853, too

[PATCH 3/3] Suricata: detect DNS events on port 853, too

[Peter Müller]

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As DNS over TLS popularity is increasing, port 853 becomes
more interesting for an attacker as a bypass method. Enabling
this port for DNS monitoring makes sense in order to avoid
unusual activity (non-DNS traffic) as well as "normal" DNS
attacks.

Partially fixes #11808

Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
Cc: Stefan Schantl <stefan.schantl(a)ipfire.org>
---
 config/suricata/suricata.yaml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/config/suricata/suricata.yaml b/config/suricata/suricata.yaml
index d7302788c..67b9e8a7d 100644
--- a/config/suricata/suricata.yaml
+++ b/config/suricata/suricata.yaml
@@ -208,11 +208,11 @@ app-layer:
       tcp:
         enabled: yes
         detection-ports:
-          dp: 53
+          dp: "[53,853]"
       udp:
         enabled: yes
         detection-ports:
-          dp: 53
+          dp: "[53,853]"
     http:
       enabled: yes
       # memcap: 64mb
-- 
2.16.4

Re: [PATCH 3/3] Suricata: detect DNS events on port 853, too

[Stefan Schantl]

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Merged.

Best regards,

-Stefan
> As DNS over TLS popularity is increasing, port 853 becomes
> more interesting for an attacker as a bypass method. Enabling
> this port for DNS monitoring makes sense in order to avoid
> unusual activity (non-DNS traffic) as well as "normal" DNS
> attacks.
> 
> Partially fixes #11808
> 
> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
> Cc: Stefan Schantl <stefan.schantl(a)ipfire.org>
> ---
>  config/suricata/suricata.yaml | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/config/suricata/suricata.yaml
> b/config/suricata/suricata.yaml
> index d7302788c..67b9e8a7d 100644
> --- a/config/suricata/suricata.yaml
> +++ b/config/suricata/suricata.yaml
> @@ -208,11 +208,11 @@ app-layer:
>        tcp:
>          enabled: yes
>          detection-ports:
> -          dp: 53
> +          dp: "[53,853]"
>        udp:
>          enabled: yes
>          detection-ports:
> -          dp: 53
> +          dp: "[53,853]"
>      http:
>        enabled: yes
>        # memcap: 64mb

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Re: [PATCH 3/3] Suricata: detect DNS events on port 853, too

[Michael Tremer]

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Do we expect any plain DNS traffic on this port?

I am not sure if any rules would match the TLS traffic here.

> On 7 Feb 2019, at 20:34, Stefan Schantl <stefan.schantl(a)ipfire.org> wrote:
> 
> Merged.
> 
> Best regards,
> 
> -Stefan
>> As DNS over TLS popularity is increasing, port 853 becomes
>> more interesting for an attacker as a bypass method. Enabling
>> this port for DNS monitoring makes sense in order to avoid
>> unusual activity (non-DNS traffic) as well as "normal" DNS
>> attacks.
>> 
>> Partially fixes #11808
>> 
>> Signed-off-by: Peter Müller <peter.mueller(a)ipfire.org>
>> Cc: Stefan Schantl <stefan.schantl(a)ipfire.org>
>> ---
>> config/suricata/suricata.yaml | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>> 
>> diff --git a/config/suricata/suricata.yaml
>> b/config/suricata/suricata.yaml
>> index d7302788c..67b9e8a7d 100644
>> --- a/config/suricata/suricata.yaml
>> +++ b/config/suricata/suricata.yaml
>> @@ -208,11 +208,11 @@ app-layer:
>>       tcp:
>>         enabled: yes
>>         detection-ports:
>> -          dp: 53
>> +          dp: "[53,853]"
>>       udp:
>>         enabled: yes
>>         detection-ports:
>> -          dp: 53
>> +          dp: "[53,853]"
>>     http:
>>       enabled: yes
>>       # memcap: 64mb