PDF SDK Security: 4 Questions Every Developer Should Ask Before Choosing a Vendor

Summary: When evaluating PDF SDK vendors, consider security more deeply to avoid future issues. In this article, we discuss key questions to ask to ensure you get the most complete information about SDK security and compliance.

Choosing the right PDF SDK is a multi-faceted problem. Capabilities, compatibility, and cost are carefully evaluated, but security compliance and vulnerabilities management are, in some ways, even more important.

Every PDF SDK on the market today offers some information about how their security stacks up, but it isn’t always clear what criteria matter most in this important part of a vendor evaluation process. PDF SDK security is different than the SaaS product security questions companies are more used to asking.

In this blog, we’ll take a look at a few important factors to consider when evaluating the security of a PDF SDK, and how to set yourself up for success.

This is an important question in any procurement process, not just for a software toolkit. There’s no substitute for the experience and expertise gained by building a product from the ground up. With a PDF SDK, this is an important security question to understand who controls and manages the code.

Some PDF SDK options on the market are deeply dependent on open-source libraries such as PDFium or other 3rd party libraries to be the main engine of the product. This means that in many ways, the security of the bulk of the product is out of their control, and dependent on third parties. Also, if that open source or third-party engine ever stopped being supported, the security of the engine would significantly degrade over time.

Those other third parties are relied upon to be the PDF expert, to understand the ins and outs of the PDF Specification, and to fix vulnerabilities within the main core of the product.

Vulnerabilities can originate at any level of the tool chain, from source code to dependencies.

By comparison, Apryse SDKs are developed from the ground up by our developers, meaning that we not only know and support our product thoroughly, but we have the ability to identify, target and quickly patch vulnerabilities at any level of the product if they arise.

SDK Software can be scanned for vulnerabilities in a few ways, and it’s important to know what’s being scanned before evaluating the results. Two common approaches to vulnerability scanning are SCA and SAST.

Software Composition Analysis (SCA) tools scan and analyze the components of software, especially open-source and third-party libraries, to identify vulnerabilities, licensing issues, and other security risks.

SCA includes:

Identifying Vulnerabilities: SCA tools detect known vulnerabilities in software components by comparing them against databases like the National Vulnerability Database (NVD).

Managing Licensing Issues: They ensure that all software components comply with licensing requirements, helping to avoid legal issues.

Generating SBOM: SCA tools create a Software Bill of Materials (SBOM), which is a detailed inventory of all software components used in an application and their licensing.

Static Application Security Testing (SAST) is a method used to analyze source code for security vulnerabilities without executing the code. It's a form of white box testing, meaning it examines the internal structure and workings of an application.

SAST includes:

So, it is crucial to understand the depth of the code scanning completed by a PDF SDK vendor.

Security certifications are an important part of compliance, especially if you need to consider how your product will meet the compliance requirements of your customers after you integrate your PDF SDK of choice. The two main certifications/reports to know are SOC2 Type II and ISO/IEC 27001.

SOC 2 (System and Organization Controls) is a compliance and privacy framework that outlines how organizations should handle customer data and related systems to ensure confidentiality, integrity, and availability. It is intended for service organizations such as cloud providers, SaaS vendors, and other web-based service providers.

The SOC 2 standards are derived from the Trust Services Criteria, which are principles and controls established by the American Institute of Certified Public Accountants (AICPA). To achieve SOC 2 compliance, an organization must undergo an independent audit by a CPA to verify that it has implemented the necessary processes to safeguard its systems and data.

Set by the International Standards Organization (ISO) and International Electrotechnical Commission (IEC), ISO/IEC 27001 is the globally recognized standard for information security management systems (ISMS), outlining the necessary requirements for an effective ISMS.

This standard offers guidance to organizations of all sizes and industries on how to establish, implement, maintain, and continuously improve their information security management systems.

Achieving ISO/IEC 27001 compliance indicates that an organization has implemented a system to manage data security risks, adhering to the best practices and principles defined by this international standard, and grows the strength of that system year after year.

SOC 2 focuses on specific data security controls while ISO 27001 requires a comprehensive Information Security Management System (ISMS). While both show a level of security, the ISO 27001 certification requires a much more in-depth, challenging audit of the ongoing management process compared to SOC2.

This is a tricky question, but an important one. Security isn’t a checkbox—it’s a mindset. Look for vendors that go beyond basic audits and actively contribute to the industry. At Apryse, we’re not only ISO/IEC 27001 certified—we’ve helped shape global PDF standards through our work with the PDF Association. That’s the kind of partner you want in your corner.

Choosing the right PDF SDK can be a complex challenge, with many criteria to evaluate. While tools that are built on free, open-source libraries like PDFium can be an excellent option for less critical or lower-budget projects, a partner with a robust code base continually developed in-house, an ongoing commitment to ISO/IEC 27001 and demonstrated leadership in the PDF industry is the right choice for others.