Vulnerability scanning plays a crucial role in an organization's cybersecurity
strategy by automating the process of identifying potential security weaknesses within the systems,
networks and applications.
This automated process helps organizations proactively detect vulnerabilities, misconfigurations,
outdated software and missing patches before they can be exploited by attackers.
Using specialized tools, vulnerability scanning highlights security risks that could otherwise
go unnoticed, making it an essential part of understanding the organization's security
posture and developing a strategy to mitigate the risks.
For example, a company might initiate a network-wide vulnerability scan.
Of course, they can use Nmap, but it would be like a manual process.
Of course, they can actually automate it using Python and bash shell scripting in
order to automate things with their Nmap, otherwise they can use tools like Nessus, OpenVAS or Qualys.
These tools scan for unpatched systems or outdated software that could be vulnerable
to exploitation, like we saw with Nmap.
The team would then prioritize patching or upgrading the software to prevent exploitation.
Similarly, vulnerability scanning can uncover other critical issues like open
ports, weak passwords, configuration issues and so on.
From a technical standpoint, vulnerability-scanning tools operate by comparing the target system
against a comprehensive database of known vulnerabilities.
The databases typically contain information from reputable resources such as the CVE, Common
Vulnerabilities and Exposures, and the NVD, National Vulnerability Database.
These databases serve as a foundation for identifying known threats.
The tools scan the target system using a combination of techniques, including network
based checks, file system inspections, and software behavior analysis.
Some vulnerability scanners even support credential scans, where the tool gains deeper insights
into the system by logging into the system and examining configurations or checking for
missing patches and outdated versions of the software.
One of the advantages of vulnerability scanning is like the automation.
It is the ability to be scheduled at regular intervals, allowing organizations to maintain
up-to-date security assessments.
This ensures that any new vulnerabilities or emerging threats are detected early.
However, while the scanning process itself is automated, manual intervention remains
necessary.
Security professionals are required to assess complex issues that may arise,
interpret the findings, and take appropriate action to remediate the vulnerabilities.
For example, interpreting the impact of a discovered vulnerability,
determining whether it needs immediate attention, and implementing the
necessary fixes all require the expertise of cybersecurity professionals.
Vulnerability scanning is a multi-faceted process that can be categorized into
three primary types, network-based, application-based, and host-based scanning.
Each type targets a different layer of an organization's infrastructure with a
specific focus on identifying potential security vulnerabilities at that layer.
These scans are critical for providing comprehensive security assessments,
ensuring that all components of an organization environment are adequately
protected.
In network-based scanning, the focus is on identifying vulnerabilities within
devices and systems connected to the network.
This scan is essential for discovering issues such as open ports,
misconfigured firewall rules, or unpatched network devices that could
be exposed to attacks.
Tools like Nessus, Nmap or Qualys are commonly used for network-based
scanning.
These tools assess public IP addresses, scanning for vulnerabilities that
could be exploited through the network.
For example, the network scan might detect an open port on a
server that should be closed or identify an outdated router with
known security flaws.
This type of scan is crucial for understanding the network's exposure
and securing its perimeter.
Application-based scanning, on the other hand, targets web applications
and their underlying software.
It focuses on identifying security flaws in the code or logic of
applications that could be exploited by attackers.
This type of scanning is often carried out using tools like OWASP ZAP or
Burp Suite by PortSwigger, namely, lately named.
These tools are designed to detect common web application
vulnerabilities, including SQL injection, cross-site scripting or
insecure APIs.
For instance, an application scan might identify a web page that is
vulnerable to SQL injection, allowing attackers to access or
manipulate the underlying database.
Application-based scanning is vital because vulnerabilities in
applications can be the gateway for attackers to compromise the
system of the organization.
Lastly, host-based scanning focuses on the individual systems within
the organization, such as servers, workstations and other endpoints.
This type of scanning ensures that the systems are securely
configured up to date with security patches and have no
missing, outdated software versions that would be exploited.
Host-based scanning tools like OpenVAS or the Microsoft-based
LAN security analyzer connect to systems or use agents to
assess configurations and software versions that are installed
inside the hosts.
For example, a host scan might reveal that a server is
running an outdated version of VirtualBox or a web server
exposing to vulnerabilities.
Host-based scanning also checks for weak access controls,
configuration issues, security hardening and insecure
configurations, ensuring the systems are properly hardened
against the attacks.
Technically, each scanning method uses different techniques
to gather and analyze data.
Network-based scans often employ techniques such as
banner-grabbing, SYN scans and vulnerability signatures.
Banner-grabbing involves collecting information from
services, running on the open ports, such as software
versions or operating systems to identify known vulnerabilities.
Application-based scans typically inspect HTTPS,
HTTP traffic, looking for vulnerabilities in the code,
using code analysis or logic of the web applications.
This scan can identify issues like improper input validation
that is on the source code, weak session management,
insecure authentication methods.
Host-based scans, on the other hand, connect to a system.
They are focused on the operating system and they rely on an
agent installed in the system to check for missing patches,
insecure configurations and outdated software versions.
These scans may also assess system logs, user permissions and
other system level settings that comes to the host analysis.
While network-based scans is generally considered less
intrusive, application-based and host-based scans can provide
more granular, in-depth details but may require more access
and permissions to the hosts.
Application-based and host-based scans are often
needed to have authentication access to the systems,
to accurately assess their configuration and their security
posture while network-based scanning can be enabled globally
in a more centralized way.
It is usually the network-based scanning, it is usually
conducted from the outside and doesn't require as much access
to the internal systems, making the less risky operation
in terms of system intrusion, however the network might be
affected because of the high traffic.