90+ Security Engineer Interview Questions and Answers

Cryptography is the practice and study of techniques for securing information and communication.

• Cryptography is used to protect data from unauthorized access.

• It involves techniques such as encryption and decryption.

• Common encryption algorithms include DES, 3DES, AES, and RC4.

• Asymmetric encryption uses different keys for encryption and decryption, while symmetric encryption uses the same key.

• Cryptography is essential for ensuring data confidentiality and integrity.

Broken authentication & authorization is when an attacker gains access to a user's account or system without proper credentials.

• An attacker can exploit this by guessing or stealing a user's login credentials.

• They can also use brute force attacks to crack weak passwords.

• Another way is to exploit vulnerabilities in the authentication process, such as session hijacking or cookie theft.

• Once the attacker gains access, they can steal sensitive data, modify or delete data, or perfor...read more

End goal is more important as it drives the overall direction and success of a project.

• End goal provides a clear vision and purpose for the project

• Procedures are important for achieving the end goal efficiently

• Flexibility in procedures may be necessary to adapt to changing circumstances

• Examples: In cybersecurity, the end goal of protecting sensitive data may require constantly evolving procedures to combat new threats

OWASP is a standard used for security testing of APIs and Web Applications

• OWASP Top 10 is a widely recognized standard for web application security

• OWASP API Security Top 10 provides guidelines for securing APIs

• OWASP ZAP (Zed Attack Proxy) is a popular tool for testing web application security

Vulnerabilities in web application penetration testing

• Injection flaws (SQL, LDAP, etc.)

• Cross-site scripting (XSS)

• Broken authentication and session management

• Insecure direct object references

• Security misconfiguration

• Sensitive data exposure

• Insufficient logging and monitoring

Zone protection DoS is a feature that protects against DoS attacks by limiting traffic to specific zones, while DoS attack rule is a specific rule that detects and blocks DoS attacks.

• Zone protection DoS limits traffic to specific zones to prevent DoS attacks

• DoS attack rule detects and blocks DoS attacks based on specific rules

• Zone protection DoS is a proactive measure while DoS attack rule is a reactive measure

• Zone protection DoS can be configured to limit traffic based on so...read more

CSRF vulnerability allows attackers to perform actions on behalf of a user without their consent.

• CSRF attacks can be prevented by implementing CSRF tokens

• The token is generated by the server and included in the form or URL

• When the form is submitted, the token is verified to ensure it matches the one generated by the server

• If the token is invalid, the request is rejected

• CSRF vulnerabilities can be exploited to perform actions such as changing passwords, making purchases, or de...read more

Broken authorization vulnerability can be extended by exploiting other vulnerabilities or by using stolen credentials.

• Exploiting other vulnerabilities such as SQL injection or cross-site scripting to gain unauthorized access

• Using stolen credentials to bypass authorization checks

• Exploiting misconfigured access controls to gain elevated privileges

• Using brute force attacks to guess valid credentials

• Exploiting session management vulnerabilities to hijack user sessions

Hard-coded secrets in code pose security threats such as exposure of sensitive information, potential unauthorized access, and difficulty in rotating credentials.

• Exposure of sensitive information: Hard-coded secrets can be easily accessed by anyone with access to the code, leading to potential data breaches.

• Potential unauthorized access: If hard-coded secrets are compromised, attackers can gain unauthorized access to systems, databases, or other sensitive resources.

• Difficulty...read more

Some python libraries used for excel file handling are openpyxl, pandas, xlrd, xlwt.

• openpyxl is a library to read/write Excel 2010 xlsx/xlsm/xltx/xltm files.

• pandas provides data structures and functions to work with structured data, including Excel files.

• xlrd is used for reading data and formatting information from Excel files.

• xlwt is used for writing data and formatting information to Excel files.

Mitigations for SQL injection include input validation, parameterized queries, stored procedures, and least privilege access.

• Implement input validation to ensure only expected data is accepted

• Use parameterized queries to separate SQL code from user input

• Utilize stored procedures to encapsulate SQL logic and prevent direct user input execution

• Follow the principle of least privilege to restrict database access rights

I once encountered an XSS attack on a web application I was working on.

• Identified the attack through unusual script tags in user input fields

• Fixed the issue by implementing input validation and encoding user input

• Learned the importance of sanitizing user input to prevent XSS attacks

• Took action by conducting a security audit of the entire application

• Implemented security best practices to prevent future attacks

I have tested various types of mobile applications including social media, e-commerce, and banking apps.

• I have tested social media apps like Facebook, Twitter, and Instagram

• I have tested e-commerce apps like Amazon, Flipkart, and eBay

• I have tested banking apps like Chase, Bank of America, and Wells Fargo

Vulnerability assessment identifies vulnerabilities, while penetration testing exploits them to determine the impact.

• Vulnerability assessment is a non-intrusive process that identifies vulnerabilities in a system or network.

• Penetration testing is an intrusive process that exploits vulnerabilities to determine the impact on the system or network.

• Vulnerability assessment is usually automated and performed regularly to identify new vulnerabilities.

• Penetration testing is usually ...read more

My forte in security lies in network security, penetration testing, and incident response.

• Specialize in network security protocols and technologies

• Skilled in conducting penetration tests to identify vulnerabilities

• Experienced in responding to security incidents and mitigating risks

• Certifications such as CISSP, CEH, or OSCP demonstrate expertise

Secure software development frameworks are methodologies used to develop software with security in mind.

• Secure software development frameworks are designed to integrate security into the software development process

• They provide guidelines and best practices for secure coding, testing, and deployment

• Examples include Microsoft's Security Development Lifecycle (SDL), OWASP's Software Assurance Maturity Model (SAMM), and NIST's Secure Software Development Framework (SSDF)

Broken Object Level Authorization (BOLA) is a vulnerability where an attacker can access unauthorized data by manipulating object references.

• BOLA occurs when an application fails to enforce proper access controls on object references.

• Attackers can exploit BOLA to access sensitive data or functionality by manipulating object references.

• Examples of BOLA include accessing other users' data, modifying data that should be read-only, and accessing administrative functions without p...read more

SQL Payload to extract sensitive data from a database

• Use UNION SELECT to combine data from different tables

• Use subqueries to extract specific data

• Use SQL injection to bypass authentication and access data

• Use ORDER BY to sort data in a specific way and extract specific data

• Use GROUP BY to group data and extract specific data

I have tested various kinds of APIs including REST, SOAP, GraphQL, and more.

• I have experience testing REST APIs which use HTTP methods like GET, POST, PUT, DELETE.

• I have also tested SOAP APIs which use XML for data exchange.

• I have worked with GraphQL APIs which allow clients to specify the data they need.

• I am familiar with testing APIs that use authentication and authorization mechanisms.

• I have tested APIs that integrate with third-party services like payment gateways, social...read more

Implement account lockout, use strong passwords, and implement CAPTCHA

• Implement account lockout after a certain number of failed login attempts

• Encourage users to use strong passwords with a combination of letters, numbers, and special characters

• Implement CAPTCHA to prevent automated brute force attacks

• Consider implementing rate limiting to restrict the number of login attempts within a certain time frame

Blind based SQL injection is a type of SQL injection attack where the attacker sends SQL queries to the database and observes the result without actually seeing the output.

• Attacker sends SQL queries to the database and observes the behavior of the application to determine if the query was successful or not.

• No error messages are displayed to the attacker, making it harder to detect.

• Time-based blind SQL injection involves sending queries that cause delays in the response time, ...read more

XSS stands for Cross-Site Scripting. It is a type of security vulnerability that allows attackers to inject malicious scripts into web pages viewed by other users.

• XSS attacks can be classified into three types: Stored, Reflected, and DOM-based.

• Attackers can use XSS to steal sensitive information, such as login credentials or session tokens.

• Preventing XSS requires input validation, output encoding, and proper use of security headers.

• Example of an XSS attack:

Questions on JavaScript concepts like hoisting, closure, arrays, string manipulation, and connecting dots.

• Hoisting refers to the behavior of moving declarations to the top of the scope.

• Closures are functions that have access to variables in their outer scope.

• Arrays are used to store multiple values in a single variable.

• To duplicate a string, use the 'repeat' method or concatenate the string with itself.

• To add to a number, use the '+' operator.

• To add three numbers, use the '+'...read more

Implemented various security measures in API development and testing.

• Implemented authentication and authorization mechanisms such as OAuth2 and JWT.

• Implemented rate limiting and throttling to prevent DDoS attacks.

• Implemented input validation and output encoding to prevent injection attacks.

• Conducted API penetration testing to identify vulnerabilities and remediate them.

• Implemented encryption and decryption mechanisms to protect sensitive data in transit and at rest.

DoS zone protection and DoS attack rule are two different methods to prevent DoS attacks.

• DoS zone protection is a feature that blocks traffic from a specific IP address or subnet if it exceeds a certain threshold.

• DoS attack rule is a security policy that identifies and blocks traffic patterns that are indicative of a DoS attack.

• DoS zone protection is a proactive measure that prevents traffic from reaching the target, while DoS attack rule is a reactive measure that blocks tra...read more

Blue team focuses on defense and prevention, while red team simulates attacks to test defenses.

• Blue team is responsible for defending against cyber threats and implementing security measures.

• Red team simulates real-world attacks to test the effectiveness of the blue team's defenses.

• Blue team works proactively to prevent security breaches, while red team works reactively to identify vulnerabilities.

• Blue team focuses on monitoring, incident response, and threat intelligence, wh...read more

Kebros is a security tool used to defend against cyber attacks by monitoring and analyzing network traffic.

• Kebros uses advanced algorithms to detect suspicious activity in real-time.

• It can block malicious traffic and prevent unauthorized access to the network.

• Kebros can generate alerts and reports to help security engineers investigate and respond to potential threats.

• Regularly updating Kebros with the latest threat intelligence is crucial for effective defense.

I would mitigate a DDoS attack on an Apache server in AWS by implementing various security measures and utilizing AWS services.

• Implementing rate limiting and access control lists to filter out malicious traffic

• Utilizing AWS Shield for DDoS protection

• Scaling up the server capacity to handle the increased traffic

• Monitoring server logs and traffic patterns to identify and block suspicious activity

• Utilizing AWS WAF (Web Application Firewall) to filter out malicious requests

Hashing is one-way function for data integrity while encryption is two-way function for data confidentiality.

• Hashing is irreversible and used for data integrity verification.

• Encryption is reversible and used for data confidentiality protection.

• Hashing produces a fixed-length output (hash value) while encryption output length can vary.

• Example: Hashing - MD5, SHA-256; Encryption - AES, RSA

Brute forcing is a method of guessing a password or encryption key by trying all possible combinations.

• Brute forcing is a trial-and-error method used to crack passwords or encryption keys.

• It involves trying all possible combinations until the correct one is found.

• This method can be time-consuming and resource-intensive.

• Brute forcing can be used for both online and offline attacks.

• Examples of tools used for brute forcing include John the Ripper and Hashcat.

Antivirus is a software that detects and removes malware. Encryption is the process of converting data into a code. Types of hacking include phishing, social engineering, and brute force attacks.

• Antivirus software detects and removes malware such as viruses, worms, and Trojan horses

• Encryption is the process of converting data into a code to prevent unauthorized access

• Types of hacking include phishing, social engineering, and brute force attacks

• Phishing is a type of hacking wh...read more

White hat hackers are ethical hackers who use their skills to improve security, while black hat hackers are malicious hackers who exploit vulnerabilities for personal gain.

• White hat hackers are ethical hackers who work to improve security by finding and fixing vulnerabilities in systems.

• Black hat hackers are malicious hackers who exploit vulnerabilities for personal gain or to cause harm.

• White hat hackers may be hired by organizations to test their security defenses, while bl...read more

I would manage the fast pace and dynamic 24*7 environment by prioritizing tasks, staying organized, and effectively communicating with team members.

• Prioritize tasks based on urgency and impact on security

• Stay organized by using tools like task management software and creating a schedule

• Communicate effectively with team members to ensure everyone is on the same page and can quickly address any security incidents

• Be adaptable and able to quickly respond to changing situations

Frida is a dynamic instrumentation toolkit for developers, reverse-engineers, and security researchers.

• Frida allows you to inject JavaScript or native code into an application to perform dynamic analysis.

• It can be used to hook functions, intercept network traffic, and bypass SSL pinning.

• Frida supports both iOS and Android platforms.

• It can be used for both offensive and defensive security purposes.

Scopes refer to the boundaries or limits of a particular security system or protocol.

• Scopes define the extent of access or control that a user or system has within a security system.

• Scopes can be defined by user roles, permissions, or other criteria.

• Examples of scopes include network access, file permissions, and application privileges.

Password spraying is a type of cyber attack where attackers try a few common passwords against many usernames.

• Attackers use common passwords to try and gain access to multiple accounts.

• Unlike brute force attacks, password spraying involves trying a few passwords against many accounts.

• Attackers aim to avoid detection by not triggering account lockouts.

• Organizations can defend against password spraying by enforcing strong password policies and multi-factor authentication.

• Exampl...read more

Pentesting methodology is a systematic approach used to identify and exploit vulnerabilities in a system to improve security.

• 1. Reconnaissance: Gather information about the target system.

• 2. Scanning: Identify open ports and services on the target system.

• 3. Gaining access: Exploit vulnerabilities to gain access to the system.

• 4. Maintaining access: Maintain access to the system for further testing.

• 5. Covering tracks: Remove evidence of the pentest to maintain stealth.

• 6. Reporti...read more

Security testing should be performed at every stage of SDLC to ensure a secure product.

• Security requirements should be defined at the planning stage

• Threat modeling should be done during the design phase

• Code review and vulnerability scanning should be done during the development phase

• Penetration testing and security acceptance testing should be done during the testing phase

• Security monitoring and incident response planning should be done during the deployment and maintenance p...read more

SSL pinning can be bypassed by modifying the app's code or using a tool to intercept and modify the SSL traffic.

• Modify the app's code to disable SSL pinning

• Use a tool like Frida or Cydia Substrate to intercept and modify SSL traffic

• Use a man-in-the-middle attack to intercept and modify SSL traffic

• Use a custom SSL certificate to bypass SSL pinning

• Use a debugger to bypass SSL pinning

nmap is a network exploration tool used to scan and map networks and identify open ports and services.

• nmap can be used to identify hosts and services on a network

• It can also be used to identify open ports and vulnerabilities

• nmap can be used to perform ping scans, TCP scans, and UDP scans

• It can also be used to perform OS detection and version detection

• nmap can be used with various options and flags to customize the scan

Registry patches can be pushed using patch management tools like SCCM or WSUS, or manually through Group Policy or scripts.

• Use patch management tools like SCCM or WSUS to push registry patches automatically

• Manually push registry patches through Group Policy or scripts

• Ensure proper testing before pushing patches to avoid any issues

OWASP top 10 is a list of the most critical web application security risks.

• It is published by the Open Web Application Security Project (OWASP)

• It includes risks such as injection, broken authentication and session management, cross-site scripting (XSS), and more

• It is updated every few years to reflect new threats and vulnerabilities

• It is used by security professionals to prioritize their efforts and focus on the most important risks

Secure authentication methods are crucial for protecting sensitive information.

• Use multi-factor authentication (MFA) to add an extra layer of security

• Implement strong password policies, including regular password changes

• Utilize biometric authentication such as fingerprint or facial recognition

• Employ single sign-on (SSO) for centralized authentication management

• Monitor and analyze authentication logs for suspicious activity

Authentication verifies a user's identity, while authorization determines what actions a user is allowed to perform.

• Authentication confirms the user's identity through credentials like passwords or biometrics.

• Authorization controls access to resources based on the authenticated user's permissions.

• Example: Logging into a system with a username and password is authentication, while being able to view or edit specific files based on user roles is authorization.

A basic XSS payload is a script injected into a website to execute malicious code on a victim's browser.

• Use the

SQL Injection is a type of cyber attack where malicious SQL statements are inserted into an entry field to manipulate a database.

• Attackers use SQL Injection to gain unauthorized access to sensitive data

• It can be prevented by using parameterized queries and input validation

• Types include In-band, Inferential, and Out-of-band

• Examples of SQL Injection attacks include UNION-based and Error-based attacks

oX in nmap is used to specify the IP protocol number to use for scanning.

• oX is followed by the protocol number (e.g. oX1 for ICMP protocol)

• It can be used with other nmap options like -sS or -sU

• It is useful for scanning non-standard protocols