Skip to main content
Welcome guest. | Register | Login | Post

security


Under... SELinux standing !

Security-enhanced Linux (SELinux) is an implementation of a mandatory access control (MAC) mechanism. This mechanism is in the Linux kernel, checking for allowed operations after standard Linux discretionary access controls are checked.
Standard Linux security is a discretionary access control model (DAC).

Discretionary access control (DAC)

DAC is standard Linux security, and it provides no protection from broken software or malware running as a normal user or root.


What does Exploit means ?
Exploit is a very small program that when utilized causes a software vulnerability to be triggered and leveraged by the attacker.

What does Buffer Overflows means ?
Buffer Overflow occurs when a buffer that has been allocated a specific storage space has more data copied to it than it can handle.

So...
Have you checked your server's log files lately ???
Did you notice something like... this !!!


Recently, I wrote an article about How to scan your Linux-Distro for Root Kits.
Now that the machine is... clean! I think, a good thing TO-DO, is to test my Firewall (AGAIN !!!)
The good news are that we can use the free tool FTester.
The bad news are that FTester needs to be configured right...

So... Let's get to work !

What is FTester ?
The Firewall Tester (FTester) is a tool designed for testing firewalls filtering policies and Intrusion Detection System (IDS) capabilities.

The tool consists of two perl scripts, a packet injector (ftest) and the listening sniffer (ftestd).
The first script injects custom packets, defined in ftest.conf, with a signature in the data part while the sniffer listens for such marked packets.
The scripts both write a log file which is in the same form for both scripts.
A diff of the two produced files (ftest.log and ftestd.log) shows the packets that were unable to reach the sniffer due to filtering rules if these two scripts are ran on hosts placed on two different sides of a firewall.
Stateful inspection firewalls are handled with the 'connection spoofing' option.
A script called freport is also available for automatically parse the log files.

The IDS (Intrusion Detection System) testing feature can be used either with ftest only or with the additional support of ftestd for handling stateful inspection IDS, ftest can also use common IDS evasion techniques.
Instead of using the configuration syntax currently the script can also process snort rule definition file.

Features:
- firewall testing
- IDS testing
- simulation of real tcp connections for stateful inspection firewalls and IDS
- connection spoofing
- IP fragmentation / TCP segmentation
- IDS evasion techniques

Requirements:
The following perl modules are required: Net::RawIP, Net::PcapUtils, NetPacket

So... we will need the Net::RawIP , Net::PcapUtils, and NetPacket Perl modules. We may also need the Net::Pcap module if it is not already installed, because the Net::PcapUtils module depends on it.
If we have the CPAN Perl module, we may install these modules with the following commands from shell:
# perl -MCPAN -e "install Net::RawIP"