No single security solution can make a network safe from all attacks. Firewalls and IPS can’t keep workstations free of viruses and malware. Antivirus can’t protect the data on a database server. Essentially, it’s a matter of balancing multiple solutions. To understand how these solutions complement each other, we need to look at some of the most common security solutions.
Peripheral Solutions
These solutions focus on the attack itself by preventing unauthorized access to network assets.
- Firewall – performing network access control at the network border. Challenges include http, which is passed, and the employee supplied device boom.
- Endpoint Protection – Exponential increase in signatures is pushing AV toward the limit.
- Intrusion Detection and Prevention Systems – IPS/IDS is also involved with a constantly evolving set of rules so that vital traffic is passed, and bad packets are blocked.
- Internal Solutions
Attackers are looking for network weaknesses, and these solutions focus on finding the weaknesses first and fixing them.
Network scanners, port scanners, IP scanners and network mappers can all assist in the detection of network assets and weaknesses.
Vulnerability Management Software – Vulnerability Management solutions first assess the network, then prioritize the weaknesses discovered so that the most important can be addressed first.
Attacks resulting in data loss are usually performed by exploiting know and well documented security vulnerabilities in software, network infrastructure, servers, workstations, phone systems, printers and employee devices.
Security flaws are constantly addressed by the vendors who issue security patches and updates on an ongoing basis. In even modest size networks making sure that all assets are running all the security patches can be a nightmare. A single host that that is missing patches or that didn’t get patches installed correctly can compromise the security of the network.
There are degrees of compromise, as not all vulnerabilities are created equal and not all assets are of equal importance or are equally available to a hacker’s access. That is where good management comes in. No security effort has an unlimited budget, so vulnerability management software helps focus the available resources on the most serious issues that exists at any one moment.
Omitting Vulnerability Management software is like securing your house with a sophisticated alarm system but leaving the door open (unresolved, known vulnerabilities). This is a vast oversimplification because networks have many hosts and each one of them has dozens of potential issues.
How does Vulnerability Management software complement other security solutions?
Every known peripheral (packet watching) security solution can be avoided under the right circumstances, but with proper vulnerability management software in place, the attacker who gains admittance to the network will not find internal weaknesses to take advantage of.
Here are some examples:
Firewall
Attackers will always try to use a legitimate network access and will eventually bypassing the firewall. Vulnerability Management software finds and helps repair the vulnerabilities that attackers are searching for. If you have no serious vulnerabilities in important assets, then your chances of data loss and dependence on perfect firewall management is reduced.
Intrusion Detection and Prevention Systems
The ideal IPS installation, with careful maintenance and using the strictest rules possible, will stop 99.9 percent of malicious packets. Given that even modest networks get thousands a day that means that only dozens get through under these idea circumstances. However, such strict settings also capture a great number of valid packets and false positive rates can exceed double digit percentages. The nearly universal solution in IPS is to stop using the strictest rules and so stop only 99 percent of the real attacks. Thus, in real world IPS installations network assets get hundreds of attack attempts and ensuring that they are free of vulnerabilities though VAM becomes vital.
Antivirus
Antivirus studies incoming packets, not the system itself to see if there is a weakness that malicious code can exploit. VAM finds the vulnerabilities and helps you eliminate them.
It is important to understand that all the perimeter security solutions can be bypassed under relatively common circumstances. Those circumstances include incomplete or improper installation or settings.
Thus, only by hardening each individual network asset can network security be improved with confidence.
Aviram holds a computer science degree from the Israeli Technion Institute of Technology, and an MBA from Tel Aviv University.
Aviram's technical background includes a degree in cryptography, development of military grade network attack and defense processes, contribution to several open-source security projects and active research in the fields of vulnerability assessment, full disclosure and protocol fuzzing. He frequently lectures and writes about advanced aspects of the security field and is the co-author of several information security related books.
Aviram splits in time between the US head office in San Jose, CA and the global headquarters in Israel.
