A vulnerability assessment is a systematic review of security weaknesses in an information system. It evaluates if the system is susceptible to any known vulnerabilities, assigns severity levels to those vulnerabilities, and recommends remediation or mitigation, if and whenever needed1. A vulnerability assessment can be performed using various tools and techniques, depending on the scope and objectives of the assessment.
Considering the potential vulnerability sources, the best initial approach to vulnerability assessment is to check for hardware and software misconfigurations to identify any possible loopholes. Hardware and software misconfigurations are common sources of vulnerabilities that can expose the system to unauthorized access, data breaches, or service disruptions. Hardware and software misconfigurations can include:
* Insecure default settings, such as weak passwords, open ports, unnecessary services, or verbose error messages.
* Improper access control policies, such as granting excessive privileges, allowing anonymous access, or failing to revoke access for terminated users.
* Lack of encryption or authentication mechanisms, such as using plain text protocols, storing sensitive data in clear text, or transmitting data without verifying the identity of the sender or receiver.
* Outdated or incompatible software versions, such as using unsupported or deprecated software, failing to apply security patches, or having software conflicts or dependencies.
Checking for hardware and software misconfigurations can help identify any possible loopholes that could be exploited by attackers to compromise the system or the data. Checking for hardware and software misconfigurations can be done using various tools, such as:
* Configuration management tools, such as Ansible, Puppet, or Chef, that can automate the deployment and maintenance of consistent and secure configurations across the system.
* Configuration auditing tools, such as Nipper, Lynis, or OpenSCAP, that can scan the system for deviations from the desired or expected configurations and report any issues or vulnerabilities.
* Configuration testing tools, such as Inspec, Serverspec, or Testinfra, that can verify the system's compliance with the specified configuration rules and standards.
Therefore, checking for hardware and software misconfigurations is the best initial approach to vulnerability assessment, as it can help identify and eliminate any possible loopholes that could pose a security risk to the system or the data.
References:
* Vulnerability Assessment Principles | Tenable
* Configuration Management Tools: A Complete Guide - Guru99
* Top 10 Configuration Auditing Tools - Infosec Resources
* [Configuration Testing Tools: A Complete Guide - Guru99]

"Boolean based" we mean that it is based on Boolean values, that is, true or false / true and false. AND Time-based SQL Injection is an inferential SQL Injection technique that relies on sending an SQL query to the database which forces the database to wait for a specified amount of time (in seconds) before responding. The response time will indicate to the attacker whether the result of the query is TRUE or FALSE.
Boolean-based (content-based) Blind SQLi
Boolean-based SQL Injection is an inferential SQL Injection technique that relies on sending an SQL query to the database which forces the application to return a different result depending on whether the query returns a TRUE or FALSE result.
Depending on the result, the content within the HTTP response will change, or remain the same. This allows an attacker to infer if the payload used returned true or false, even though no data from the database is returned. This attack is typically slow (especially on large databases) since an attacker would need to enumerate a database, character by character.
Time-based Blind SQLi
Time-based SQL Injection is an inferential SQL Injection technique that relies on sending an SQL query to the database which forces the database to wait for a specified amount of time (in seconds) before responding. The response time will indicate to the attacker whether the result of the query is TRUE or FALSE.
Depending on the result, an HTTP response will be returned with a delay, or returned immediately.
This allows an attacker to infer if the payload used returned true or false, even though no data from the database is returned. This attack is typically slow (especially on large databases) since an attacker would need to enumerate a database character by character.
https://www.acunetix.com/websitesecurity/sql-injection2/