The Ultimate Guide to Software Penetration Testing for SaaS Companies

Introduction

1230 ransomware incidents were reported in North America in the 2024 third quarter alone.

The worldwide digital ecosystem has seen an unparalleled rise in cyber attacks. It has seen a significant increase in both the frequency and intensity of cyber attacks against businesses, giving insight on hackers' shifting techniques and the urgent need for software penetration testing.

SaaS (Software as a service) being the emerging industry, companies are facing greater criticality of risks with the rise in cloud infrastructure adoption, nature of sensitivity of data being handled, and the multi-tenant environments.

Understanding and being proactive to securing your business and its assets through SaaS penetration testing gives you greater leverage in the ever expanding competitive technological world.

This blog is to help you understand the nooks and corners of software penetration testing for SaaS companies and why it is critical for your security posture.

Security testing for SaaS might be easy or hard due to various reasons like the infrastructure complexity, dynamic advanced threat landscape, and acute global talent shortage. Still, it is mandatory.

What is Software Penetration Testing?

The primary purpose of a software penetration testing is to identify threats an attacker can exploit. It helps to conduct security risk assessment in a much more reliable and efficient manner through simulating attacks.

Software penetration testers are the experts behind all techniques of securing your SaaS business and its applications. They will be given the objective along with a standardized checklist on what all to be checked during the test.

A penetration test report is then created which contains all the findings, procedure and process involved, remediation suggestions and the degree of criticality of vulnerabilities present in your assets.

Application testing for web and mobile, network, API, and cloud infrastructure are the most common infrastructure checked in a SaaS penetration testing.

Why Do SaaS Companies Need Penetration Testing?

As with every penetration testing on various target assets, the goal of SaaS penetration testing is to identify, classify, and mitigate the software risks at the earliest. This helps towards better business profitability, customer reputation, competitive advantage, and security compliance to various data privacy and security regulations.

A SaaS application typically is maintained on your company servers or third party cloud-storage and accessed via the internet. This delivery strategy has various advantages, including reduced expenses and easier maintenance. Nonetheless, it poses threats from data breaches, weak APIs, shady employees, hijacking accounts (also known as account takeover), and phishing.

The SaaS penetration test addresses the applications, front-end and back-end APIs, as well as an in-depth assessment of external-facing assets. Third-party software security testing is the most effective technique to verify the infrastructure of SaaS systems and boost confidence by finding and reducing security threats.

The increase in attack surface with technological expansion across the globe is yet another concern. SaaS applications being in need to be online around the clock, the risk of being susceptible to cyber attacks are ever expanding.

Key Components of a SaaS Penetration Testing Plan

Scope definition

Outlining the boundaries and areas to be tested are done in this phase to ensure focused and efficient security assessment. What is in-scope (frontend user interface, backend databases, and authentication systems) and out-of-scope such as production environments which are usually highly sensitive to testing are defined. Setting these helps to conduct the penetration test in a better manner without affecting the live functioning of the application.

Reconnaissance

Once the scoping is done and necessary approvals are obtained from your decision makers, next comes the reconnaissance phase. The intelligence about the target system is obtained through various techniques such as passive and active reconnaissance. A comprehensive blueprint of the SaaS application is created which would relevant data about the target asset and its infrastructure. This helps define a solid foundation for upcoming stages. Better accurate the information gathered, best will be the test result

Threat modeling

Threat modeling analyses and informs data about threats that may affect a certain system or network. It allows us to understand the nature of vulnerabilities and their impact on the asset. It differs based on the system under investigation. However, almost every tech-dependent company function may benefit in some manner. It also allows you to narrow down the scope of risks to a specific process or system before investigating them.

This clears up any uncertainty about what issues exist and how to protect against them. Also, it provides IT teams with the knowledge they need to defend the system far in advance of an attack.

Vulnerability assessment

Vulnerability assessment focuses on identifying and evaluating vulnerabilities in your application. Combinations of automated and manual tools are often used in this process for scanning. Outdated systems, misconfigurations, common vulnerabilities such as injection and scripting attacks are found in this phase.

Penetration testing

Once the vulnerability assessment is complete, next comes penetration testing. More sophisticated vulnerabilities including the business logic errors and privilege escalation are detected in this phase. It is important to understand context-dependent vulnerabilities through real-world-like attack simulation. The effectiveness of the defense mechanisms of your applications can be understood which includes the depth to which an attacker can intrude to your application.

Penetration testing helps to understand how deep and bad an attacker can enter into your business to cause catastrophic incidents.

Documentation

Once the test is done, all the findings, vulnerabilities, attack vectors, and recommendations are documented into a report to ensure clear communication with the stakeholders. It provides end to end record of the testing process, with areas of concerns highlighted along with actionable remediation steps.

Generally it follows the structure of executive summary, scope and objectives, methodology, findings, risk assessment, recommendations, remediation tracking, conclusion and appendices.

Types of software penetration tests

Software penetration testing can be primarily classified into three. It is based on the preliminary data about the asset and organization given to the penetration tester prior to the test.

They are:

1. Black box penetration testing

A black box pen test is a penetration test that is performed externally. In this technique, testers, often known as penetration testers, are unaware of the code, architecture, or system design. Black-Box Penetration Testing simulates real-world assaults on your business assets and infrastructure. They access the environment as unauthorized external users, similar to an intruder attempting to breach security.

2. White box penetration testing

White box testing includes testing a system or application with an adequate understanding of its internal workings. It can be very precise and concentrated since the tester has previous knowledge of the system's internal workings, allowing for a focused examination of specific weak points or regions of vulnerability. Compared to black box tests it is expensive due to the need for additional time and skill to fully understand and evaluate the system. Could be impacted by the tester's prior knowledge of the system.

3. Gray box penetration testing

Gray box penetration testing is in the center when it comes to prior knowledge provided to the tester, offering a partial understanding of the system's internal workings while maintaining an outward perspective. It combines the black box and white box penetration testing methods, giving the tester some understanding of the system but not complete knowledge or access. The cost will be balanced because it requires a certain amount of experience and knowledge, but not to the same extent as the white box test.

Tools and techniques used

SaaS penetration testing utilizes a variety of tools and techniques in all phases of penetration testing from identifying vulnerabilities, exploit weaknesses to documentation.

Following are some of the common tools and techniques used classified based on each stage of penetration testing techniques.

1. Reconnaissance Phase

Tools

• Shodan: Security search engine which helps to gain data on exposed devices, services, and systems using proper queries.
• Maltego: Used for open source intelligence on data visualization and mining
• AMASS: [Brief description of AMASS]
• Recon-ng: Used for reconnaissance through leveraging various modules within.

Techniques

• DNS Enumeration: Domain information is analyzed in this technique for initial information.
• Google Dorking: Finds publicly exposed files, sensitive data, or vulnerable endpoints using specialized queries in search engines.
• WHOIS Lookups: Details on domain ownership and registration are collected.

2. Threat Modeling Phase

Tools

• OWASP Threat Dragon: Open source software used in threat modeling.
• IriusRisk: Tool for creating threat models for software and cloud architectures, as well as managing such risks and countermeasures across the SDLC.

Techniques

• Data Flow Diagrams (DFDs): Used to illustrate the data flow channels and exposing the hidden flaws in your system for a simpler technical representation.
• Attack Trees: Visual representations on how your system or network can be attacked by a bad actor earlier.
• Mitigation Mapping: Strategies are developed and documented to identify, assess, prioritize and thereby reduce the impact of potential security threats.

3. Vulnerability Scanning Phase

Tools

1. Nessus: Used to find misconfigurations and vulnerabilities in applications
2. OpenVAS: Open source scanning tool to detect publicly known vulnerabilities.
3. Nmap: Network scanning tools used to analyze ports and services.
4. Nikto: Useful to find outdated software, misconfigurations, and vulnerabilities in web servers.
5. Burp Suite: Comprehensive vulnerability scanner and proxy with features to check for vulnerabilities such as injection and scripting attacks on applications.

Techniques

1. Port Scanning: Open ports and services on the target systems are assessed in this technique.
2. Banner Grabbing: Service information that contains versions and vulnerabilities of the applications are collected
3. Automated Scanning: Common vulnerabilities are scanned using existing or tailor made tools.

4. Penetration Testing Phase

Tools

1. Metasploit Framework: Used to develop and execute exploits based on vulnerabilities against target systems.
2. SQLmap: Used for automated detection and exploitation of SQL injection vulnerabilities.
3. BeEF (Browser Exploitation Framework): Abbreviation for browser exploitation framework which helps test client-side vulnerabilities in web browsers.

Techniques

1. SQL Injection: Data stored in the database is extracted using malicious inputs.
2. Cross-Site Scripting (XSS): Malicious scripts are injected into web applications in turn affecting the users by stealing session cookies and impersonating others' identity.
3. Privilege Escalation: Check for possibility to jump from initial least privilege to higher is done in this technique to check for compromise of the confidentiality, integrity and availability of the SaaS application.
4. Remote Code Execution (RCE): In remote code execution (RCE) check, a penetration tester runs a test for the possibility of executing malicious programs on your SaaS application or network that launches arbitrary code on a distant device while linking over public or private networks of a threat actor.

5. In documentation phase

Tools

1. Dradis: Open source collaborative tool which helps manage security assessments and generate reports in a simplified manner.
2. Faraday: Faraday collects and converts the penetration test output data you import, enabling you to examine it in many visualization styles and choosing relevant and understandable ones to both managers and analysts.
3. PwnDoc: It is a pentest documentation program that makes it simple for you to record the findings and create a customisable Docx report format. Custom-built:

Best practices for SaaS penetration testing

Following are the industry expert recommended best practices when it comes to SaaS penetration testing:

Regular Testing Cycles:

SaaS applications being trending and the favorite target of threat actors, the frequency of performing penetration testing is always better to be considered primarily based on factors such as complexity of the system and sensitivity of data being handled.

Finding a balance between performing SaaS penetration testing quarterly for high risk systems and biannual for less critical systems are always suggested. Also, ensuring continuous testing in between these periods is highly recommended since it helps to detect potential or active vulnerabilities minimizing the risk window between.

Integrating automated testing in the CI/CD pipelines also helps your developers to ensure secure build and release of the SaaS application.

Integration with SDLC (Software Development Life Cycle):

Shift left security is the technique of conducting security testing early in the software development cycle itself rather than waiting to be conducted in the post-production environment.

This approach is greatly proactive since it incorporates static and dynamic application security testing (SAST/DAST) tools in the SaaS application towards better security. Better code reviews, adopting secure code practices, and threat modeling while in the development phase prevents risks in the production environment of the application.

Securing APIs and Microservices:

SaaS applications being heavily dependent on the API (Application Programming Interface) and micro services, attackers often target weaknesses in them, usually to gain unauthorized access or exfiltrate sensitive data.

Implementing proper authentication mechanisms such as mutual TLS, OAuth, and OpenID Connect is one of the most suggested security practices when it comes to securing the APIs.

Ensuring proper authorization and access controls and not exposing sensitive endpoints, implementing rate limiting to prevent brute force attacks, and ensuring input validation to prevent injection, scripting, and overflow attacks are considered as the best practices.

Cloud Security Considerations:

The majority of the SaaS applications are hosted in cloud environments such as AWS and GCP. These infrastructures are susceptible to misconfigurations, insufficient logging, and improper access control settings.

Conducting proper testing helps to prevent these additional attack vectors up to a greater extent. The misconfigurations include poorly set up IAM (Identity and Access Management) roles, insecure storage buckets, and unencrypted databases.

Additionally, ensuring all the sensitive data are encrypted in rest, process, and transit phases are recommended. Ensuring proper management of cloud based KMS (Key Management Service) is also preferred.

Common Vulnerabilities in SaaS Platforms

1. CrossSite Scripting (XSS)

Cross-site scripting is a type of software attack that occurs at the program end of a web application in order to obtain information from an unsuspecting client. It is accomplished by inserting poisonous lines of code into the initial code of a reputable online application.

2. Business logic

It is reported when the application’s design or functionality is exploited allowing the attacker to misuse the application’s intended operation. What makes this vulnerability stand out is that it often doesn’t trigger any warnings in security mechanisms such as firewalls or intrusion detection systems. It is caused based on how the business implements rules in the SaaS application rather than misconfigurations or bugs in the software part.

3. Access control vulnerabilities

Occurs when SaaS application fails to enforce rules properly on what an authenticated user can do and can not. This vulnerability allows the bad actor to access information and perform actions that are not permitted, while they are in a particular role.

4. Insecure Authentication and Authorization

Authentication verifies an individual, whereas authorization determines if the identified user holds the relevant permissions for a certain action. Insecure authorization can arise where an entity fails to authenticate someone or a user before running a requested API endpoint from a SaaS service, as it is very hard to complete permission tests on an inbound request without knowing the caller's identity.

5. Server Side Request Forgery

The adversaries make unauthorized requests to the SaaS web application’s internal or external systems from the servers. The attacker will be able to confuse the server to send requests on their behalf to bypass the network controls, gain access to confidential internal services, or retrieve sensitive information.

6. Insecure API endpoints

They are the application programming interfaces which don't have the sufficient security measures. This makes them susceptible to a variety of attacks including data breaches, unauthorized access, and other security issues. Bad actors can exploit these endpoints to gain unauthorized access and obtain sensitive information towards causing operational disruption and reputational loss to your SaaS business.

Engaging a Professional Penetration Testing Provider

The choice between a team of internal penetration testers and external is by considering factors such as company size, expertise, budget and the business security requirements.

The in-house team would obviously be greatly familiar with the SaaS application since they interact with them much more frequently from its planning to release phases. For them, the time to respond to an incident will be higher and will be quickly capable of integrating with internal security needs and processes.

However, finding, training, and maintaining a dedicated team can incur higher costs to your firms due to various factors including salaries, benefits, and providing them training to latest TTPs (Tactics, Techniques, and Procedures). The broadness of experience and knowledge as compared to external experts will be much lower for them, especially in terms of niche areas or complex attack vectors.

What to Look for in a Penetration Testing Provider:

Relevant experience, certifications, qualifications, clarity of reporting, and testing methodology they follow is to be looked at primarily when it comes to choosing and external penetration testing as a service provider.

Their experience in the SaaS industry helps greatly to understand newer kinds of challenges towards addressing them effectively.

Following are some of the infamous and industry recognized certifications to be considered based on your business and industry demand:

1. OSCP (Offensive Security Certified Professional)
2. CEH (Certified Ethical Hacker)
3. CISSP (Certified Information Systems Security Professional)
4. CREST (Council of Registered Ethical Security Testers) or CHECK certifications

When it comes to testing methodology, there are globally recognized ones and tailored ones by service providers for your specific business demands. OWASP frameworks is an example for the same.

An actionable report supported with good description regarding vulnerabilities, its nature of criticality, and remediation suggestions comes really helpful towards better fixation.

Conclusion

Software penetration testing is important towards better business continuity and maintaining reputation and compliance to data privacy laws. Securing your SaaS application might be hard and costly with the ever dynamic and evolving threat landscape.

Making the right choices is also important when it comes to choosing the right partner in securing your SaaS application.

With UprootSecurity, you gain access to a wealth of pioneer cybersecurity experts handpicked from the industry with an innovative pricing approach of pay per vulnerability model.