Why have a Network
Security Audit (NSA)?
In this age of
distributed computing and of client-server and Internet-enabled information
access, computer security consistently rises to the top of most “important
issues” lists. This is a difficult question to answer, because it depends on
your organization’s ability to manage the proliferation of company systems
and the interactions between them.
Many times,
more systems and/or more interconnections (access) are added to your
network, without fully testing how these additions might compromise overall
system security. This can be an entry point for the enemy. To answer this
question properly, you will need to have a comprehensive network security
audit performed.
NSA
Overview
To get the best
overall picture of a network, security must be assessed from several points
of view. These perspectives range from the physical security of systems, to
the configuration of the firewalls, to the trustworthiness of workers. The
history of industrial espionage has been part of the physical world and thus
numerous practices have been developed to handle this traditional portion of
security problems. The age of network-based industrial espionage has had a
brief history and thus has less developed security assessment practices.
The security
profile of a network of systems can be assessed from three principal vantage
points.
-
From outside the Enterprise
- the view of the
systems infrastructure through the firewall.
-
From inside the Enterprise
- the view of systems
from behind the firewall.
-
From the Host
- the view from the actual operating system of
the individual servers and workstations.
Each of these
perspectives will reveal unique security vulnerabilities. Removing the
vulnerabilities as seen from outside the enterprise is the first step to
halt the efforts of the casual hacker in the industrial espionage age.
Removing the vulnerabilities as they appear from behind the firewall
accomplishes two goals. It creates a second line of defense should the
firewall become compromised. It also creates a defense for the “blitzkrieg”
attack around the firewall through a modem or other non-protected entryway.
Finally
evaluating security from the systems themselves will close vulnerabilities
that could be exploited through a firewall or from other systems on the
network. It also hardens the security of the network, restricting the
avenues of attack for the disgruntled employee or contractor.
The
Perimeter
The
above-mentioned vantage points are what CCI refers to as the Perimeter. To
further delineate the perimeter, the following specifies target areas of the
NSA.
Firewall
Many
enterprises erect a firewall as the first and often only line of defense for
their information systems. A firewall is a device that controls the flow of
communication between internal networks and external networks, such as the
Internet.
Many
corporations assume that, once they have installed a firewall, they have
reduced all their network security risks.
A firewall must
be configured to allow appropriate traffic and to deny or restrict
inappropriate traffic. The configuration process can be highly susceptible
to human error. In a dynamically changing environment, system managers
routinely reconfigure firewalls without regard to security implications.
Access control lists on a firewall can be numerous and confusing. You must
be sure that the firewall has been set up correctly and that it is
performing well.
Hosts
(Servers)
Servers, in
many cases, are a company’s crown jewel. While threats and misuse of network
segments and expensive communication links are high in the food chain of
security, servers contain a company’s most valuable asset. Attacks on these
servers can result in theft of intellectual property, loss of revenue, and
an astronomical recovery cost.
Network
Segments
Sometimes, it's
what we don’t know that can hurt us. At any given time there could be
hostile content moving about our network segments. We work toward a lockdown
of our servers and gateways, but if we overlook the wire itself, then we
have lost the war. An example of this is a disgruntled employee who launches
an attack against corporate mission critical servers or when an enterprising
employee sets up a self-profiting website on a server of his own or even
worse, one of the corporate production machines. While all segments in a
large enterprise network are vulnerable, history has shown the largest
amount of hostile activity has been focused on the network segments
surrounding the firewall and where the production servers reside.
CCI
Reporting System
Combines
data from various “best of class” security tools into one database producing
meaningful “high level” reports that management can use to better understand
the vulnerabilities within their information enterprise.
The Detail
Reports create a “scope of work” for the IT staff or outside firm to address
vulnerabilities on the network.
Information
Testing Protection
The host-based
and network-based auditing tools used by CCI do not affect or remove any
enterprise data. Information is collected about the state of systems and
networks designated in the scope of an audit. Resources are enumerated, and
vulnerabilities are revealed and reported on, but no systems will be
actively exploited.
All information
will be maintained on the CCI collector server in an encrypted format.
Delivery of the final security document, which will contain information
about compromised system information and vulnerabilities, will be restricted
to pre-designated company officers.
Scanning methodology:
CCI
uses an
assortment of progressive scanning technologies. These technologies
correlate vulnerability information and uses information from one part of
the scan to search deeper for weaknesses in the network, allowing
information obtained from one break-in technique to be used by another. This
provides an “exterior”, unprivileged, network assessment view – essentially
reporting security weaknesses that may be visible to hackers. All possible
TCP and UDP ports (1 – 65,536) are scanned quickly (hundreds of ports on
each system of a class-C network
per hour) — for
improved performance and execution time. Each network is automatically
enumerated and scanned for over 450 individual vulnerabilities. The scan is
conducted as follows:
1. Identify
network resources, including computer names, IP addresses, alias
information, operating system, version, etc.
2. Look for
problems that are simple to detect, using a selective scan for services
known to have vulnerabilities, such as SMTP.
3. Perform a
complete TCP and UDP port scan and looks for a broad range of
vulnerabilities in common service protocols, such as NIS, HTTP, FTP, NFS,
SMB, IRC, SMTP, SNMP, BIND, etc.
4. Check for
vulnerable Windows registry keys.
5. Uses the
system and services information to exploit high-risk vulnerabilities.
6. Cracks
passwords.
7. Attempts to
login to systems with privileged level access.
CCI
will
utilize host-based and remote Vulnerability Assessment tools that
proactively identifies security vulnerabilities before they are exploited. A
host-based assessment means deeper, more accurate scans, high efficiency,
and minimal false positives. It permits the systematic planning, management,
and control of your security policy and risks from a single location.
These tools
report security compliance from enterprise-wide view down to individual
security settings. The agents installed on each host utilize encrypted
communications and databases. This design protects enterprise data from
being compromised during or after an audit. During an actual policy run, the
agent and associated processes run at the lowest possible execution
priority, avoiding interference with other running applications or services.
Our security
audit tools supports most operating systems and integrates easily into your
existing security applications and processes.
By having an
agent on the machines to be assessed, CCI is able to review settings that
are not capable of being reviewed from a network scan, such as patch levels
and policy settings for password aging, and only reports back the items that
fail or are not compliant with the checks that are preformed. This greatly
reduces network traffic.
Security
vulnerabilities assessed include:
-
Weak passwords
-
Unauthorized privileges
-
Improper changes to security settings or files
-
Incorrect file access
-
Out of date patch levels
-
Incorrect system configuration
Summary
CCI has defined
the perimeter as three target areas: Firewall, Hosts and Network Segments
surrounding the firewall. With the high cost of consulting engagements and
the plethora of security assessment offerings on the horizon, companies are
faced with a daunting task of choosing the right partner to assist in
addressing their security needs.
CCI has
simplified the process by narrowing the focus to the highest risk areas
within the network.
The following
solutions are incorporated in a NSA, with more detailed information
available in the subsequent Preliminary Scope of Work:
Benefits
-
Independent, cost effective and system-based
assessment will be completed in weeks, not months.
-
Utilize “best of class” vulnerability assessment
tools.
-
Shows due diligence to senior management,
customers and investors.
-
Reduces exposure to information theft and abuse.
-
Confirms vulnerability status of network.
-
Encourage maintenance of security standards.
1.
Detailed Q&A with
customer’s IT staff
In order to
successfully complete the discovery and analysis, CCI will require the
customer’s IT staff to complete several questionaires and technical forms
that will greatly assist CCI during the discovery phase .
2.
Firewall Configuration Analysis
The CCI
Security Engineer (SE) will arrive onsite and meet with security
administrator. An interview with this customer resource will reveal the
router configuration, the current firewall configuration and rule-base. This
will be documented by the SE and entered into our automated data collection
system for presentation in the final report. A detailed diagram of the
network segments surrounding the firewall will be produced from this
information.
3.
Penetration Test
Vulnerability assessment through firewall to specific targets
The SE will
perform a vulnerability assessment through the firewall from multiple
vantage points. This process will target specific segments and look for both
violations of access and denial policy. The exam will include, but not be
limited to
snooping,
scanning and password cracking attempts to machines sitting in all zones
surrounding the firewall. In addition, this exam will attempt to enumerate
operating system versions and patch levels, applications and services, users
and connections. CCI will introduce assessment software(s) into the
Customer’s data center and attach to the corporate network in order to
perform the scans.
4.
Host (Server) OS Assessment
The SE will
establish a working set (group of servers) for which assessments are to be
performed. Once the working set has been selected, the SE will perform a
vulnerability assessment on each of the servers in the working set. This
examination is prepared using a policy-based approach. The policy is a set
of platform specific checks approximately 1500 known and unknown
vulnerabilities within the OS. CCI will conduct audits on the hosts selected
by the customer:
5.
Vulnerability
assessment of private network – selected segments
SE will perform
a vulnerability assessment on specific internal segments and will look for
both violations of access and denial policy. The exam will include but not
be limited to snooping, scanning and password cracking attempts to machines
sitting in all zones surrounding the firewall. In addition, this exam will
attempt to enumerate operating system versions and patch levels,
applications and services, users and connections.
Assumptions
The discovery,
assessment and reporting phases of the project is estimated to take
approximately three weeks. It is assumed that:
-
Customer will make space available for the SSE
and associated equipment.
-
Individual audits will be scheduled at the
convenience of Customer IT management
-
Customer will make internal resources available
to work with CCI as necessary to perform the audit
NSA Deliverable and
Presentation
When all audits
have been completed, CCI will remove the collection tools from the Customer
data center. The collected data will then be analyzed and assembled into the
final report. The full NSA includes:
NSA Definition
Scope of Work
Executive
Overview with Graphical Reports
Penetration
Test Detail Reports
Host (Server)
OS Assessment Detail Reports
Private Segment
Scan Detail
Executive
summary overview report with recommendations
Conclusion
The security of
your information enterprise is an ongoing effort. Performing the NSA is just
the first step.
Our methodology
is designed to identify a strategy that addresses a responsible approach to
maintaining the integrity of your Security Enterprise.
The following
steps are recommended best practices:
-
Perform NSA and present documented security
vulnerabilities and recommended solutions.
-
Within 10 days following the NSA presentation,
CCI leads Project Planning meeting to determine timeline of
implementation solutions to address vulnerabilities.
-
Within 45 days of NSA presentation, CCI meets
with IT staff to determine status of implementation plan.
-
Schedule NSA to re-audit environment within 90
days of first NSA .
-
Perform NSA to determine the success of
implementation effort within 90 days of first NSA .
-
Present NSA and document progress of security
effort.
-
Repeat 2 through 5 above at defined intervals (at
least annually)
Estimation of
labor:
According to
the current information provided to us, by the client, we can calculate the
approximate man-hours it will take to complete the NSA project (site
visit, local/remote discovery, analysis, report preparation with
recommendations, final consultation and review of findings with client).
The actual total time will vary, depending on the accuracy and depth of the
information provided to us by the customer’s IT staff, as well as the level
of access granted to the entire network infrastructure. All labor rates will
be billed according to the customer’s current service plan or prepaid block
time (BT) plan.
Agreement:
In order
to complete this network security audit in the most timely and effective
manner,
the customer must agree to, and authorize Courtesy Computers full access to
all necessary members of the customer's staff, vendors, network,
documentation, software, licensing data, and ancillaries associated with
their network infrastructure. Courtesy Computers, Inc. will abide to a
confidentiality agreement regarding the customer’s private information.