Server hacked on known port Post: 303029984

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Special Forums Cybersecurity Server hacked on known port Post 303029984 by bakunin on Monday 4th of February 2019 06:37:06 AM

02-04-2019

Registered User

If i remember correctly 1521 is one of the standard ports for the Oracle listener, so i suppose you have an Oracle database running there. That the listener listens is quite as it should be, no?

What makes you think the server "was hacked"?

I mean, iptables is just a packet filter and as such it cannot discern between legitimate content and an illegitimate one. It filters packets based on IP address (layer 3) and port (layer 4), nothing more, nothing less. Obviously you need to allow traffic to the configured port of the listener otherwise the database would not be usable. So either you allow this port or you disable it (eventually restricting to a certain range of IP addresses), but what content goes over this port (i.e. legitimate database queries vs. malicious content) the packet filter is the wrong tool to assess. For that you will need a "stateful inspection" type of firewall which iptables is not.

Also be aware that the concept of "host based firewalls" is a flawed one per design. A hosts role is either providing a service (that is: some application) OR providing firewall services, but not both! The reason is you don't want the host you want to protect run the firewall itself, beause in this scenario the malicious packages already have reached the interface they are trying to attack. You want the firewall in front of (and separated from) the host you try to protect so that the malicious content doesn't even reach the interface you want to protect.

I hope this helps.

bakunin

Last edited by bakunin; 02-04-2019 at 05:08 PM.. Reason: confused "stateful inspection" with "deep state inspection" - oh, the paranoia

bakunin

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LEARN ABOUT MOJAVE

net::server::proto::unix5.18

Net::Server::Proto::UNIX(3)				User Contributed Perl Documentation			       Net::Server::Proto::UNIX(3)

NAME

       Net::Server::Proto::UNIX - Net::Server UNIX protocol.

SYNOPSIS

       See Net::Server::Proto.

DESCRIPTION

       Protocol module for Net::Server.  This module implements the UNIX SOCK_STREAM socket type.  See Net::Server::Proto.

       Any sockets created during startup will be chown'ed to the user and group specified in the starup arguments.

PARAMETERS

       The following paramaters may be specified in addition to normal command line parameters for a Net::Server.  See Net::Server for more
       information on reading arguments.

       unix_type
	   Can be either SOCK_STREAM or SOCK_DGRAM (default is SOCK_STREAM).  This can also be passed on the port line (see Net::Server::Proto).

	   However, this method is deprecated.	If you want SOCK_STREAM - just use proto UNIX without any other arguments.  If you'd like
	   SOCK_DGRAM, use the new proto UNIXDGRAM.

METHODS

       NS_unix_path/NS_unix_type
	   In addition to the standard NS_ methods of Net::Server::Proto classes, the UNIX types also have legacy calls to NS_unix_path and
	   NS_unix_type.

	   Since version 2.000, NS_unix_path is simply an alias to NS_port.  NS_unix_type is now redundant with NS_proto.

	   These methods were missing between version 2.000 and 2.003 but have been returned as legacy bridges.

QUICK PARAMETER LIST

	 Key		   Value		    Default

	 # deprecated UNIX socket parameters
	 unix_type	   (SOCK_STREAM|SOCK_DGRAM) SOCK_STREAM
	 port		   "filename"		    undef

	 # more recent usage
	 port		   "filename / UNIX"
	 port		   "filename / UNIXDGRAM"

LICENCE

       Distributed under the same terms as Net::Server

perl v5.18.2							    2012-06-06					       Net::Server::Proto::UNIX(3)