[CentOS] BIND server getting DDOS

Thu Aug 4 15:22:56 UTC 2022
Mark Milhollan <mlm+centos-lists at milhollan.com>

On Wed, 3 Aug 2022, Gordon Messmer wrote:
>On 8/3/22 11:08, Mark Milhollan wrote:

>>Usually that's someone hoping to use you in a reflection attack
>
>Doesn't a reflection attack require the reflecting server to answer queries?  
>I'd think that the server logging that the query was denied would indicate 
>that it is not vulnerable to that type of abuse.

The server did send a DNS response packet to the apparent sources, just 
not as large as an attacker usually hopes for -- a referral is 800+ 
bytes vs REFUSED which is about 30.  So a successful reflection but not 
quite the level of attack desired.

The source addresses might be correct but in that case the systems are 
misconfigured since they want to resolve the root to an IP address, 
perhaps due to a recent update.


/mark