Security built in from the start performs better than security bolted on at the end. As cyber threats become more targeted, the gap between designed-in security and patched-on security is where attackers focus their attention. That principle sits at the heart of the secure by design movement and has direct implications for how you evaluate and vet the vendors you work with.
If a vendor’s software was built without security as a core design philosophy, no amount of post-deployment patching will fully close the gaps left open during development.
What Secure by Design Actually Means
Secure by design (SbD) is a development methodology in which security features are treated as foundational requirements from the outset rather than an afterthought. Security is addressed early in the development process, not bolted on once a product is ready to ship. Software built on SbD principles defaults to a secure state. It’s not something users have to enable or configure themselves.
The Cybersecurity and Infrastructure Security Agency (CISA), the National Security Agency (NSA), the UK Government, and a coalition of international partners issued joint guidance on what a secure-by-design approach should look like in practice. The ambition is straightforward: shift cybersecurity risk away from customers and onto the manufacturers that build the software. Both the US and UK governments have since built SbD requirements into how they buy software and build infrastructure. SecurityScorecard was among the organizations that signed the CISA Secure by Design pledge and has publicly documented its commitment to those goals.
The Three Core Principles
CISA’s framework asks software manufacturers to commit to three things:
- Take ownership of security outcomes rather than passing responsibility to users through configuration requirements
- Embrace transparency and accountability by publishing vulnerability disclosure policies and sharing data on measurable actions taken to reduce entire classes of flaws
- Build organizational commitment to security by making secure software development a leadership priority with dedicated resources and a clear design process
Why Does This Change How Vendor Vetting Should Work?
Most vendor vetting still leans heavily on compliance frameworks, questionnaire responses, and assessments that capture a single moment in time. SbD pushes the question further back: did the vendor build security in from the beginning, and do they actually intend to keep it that way?
When a product wasn’t designed with security in mind, it leaves exploitable flaws that stay open long after deployment. Security threats that a design review would have caught early become structural weaknesses that persist across every version the vendor ships. A genuine SbD posture adopts an assume-breach mentality. It applies zero-trust principles from the architecture level up, rather than treating perimeter defense as the primary line of protection. Most supply chain attacks don’t succeed because of a sophisticated zero-day exploit. They succeed because a vendor shipped software with weak defaults, poor least privilege controls, or no real assumption-of-breach thinking baked in.
What to Look for in a Vendor’s Secure Design Posture
When you’re vetting a vendor, push past the general security claims and ask specific questions. Our guide on cybersecurity questions to ask your vendors covers this in depth, but for SbD specifically:
- Have they signed the CISA Secure by Design pledge? If so, what have they actually done to back it up?
- How is threat modeling integrated into their development lifecycle, and does penetration testing occur before release?
- Is multi-factor authentication (MFA) enabled by default across their products and secure websites, or is it something customers have to configure themselves?
- How do they manage open-source components, and how fast do they actually patch known vulnerabilities?
- Do they follow NIST (National Institute of Standards and Technology) guidance on secure software development?
- What’s their vulnerability disclosure policy, and how quickly do they communicate security issues to customers?
When you build these questions into your vendor selection criteria, you’re doing something important. You’re promoting best practices across your supply chain and signaling to the market that a genuine SbD commitment is a real procurement requirement. Vendors who publish their vulnerability data, maintain secure infrastructure, and show their work are the ones worth trusting.
From Vetting to Continuous Assurance
Vendor vetting is a point-in-time activity. SbD assurance needs to be continuous. A vendor who signs the pledge today may drift from those commitments as product teams change and deadlines compress. The security requirements they pledged to implement can get deprioritized under delivery pressure.
This is where the attack surface tells a story that questionnaires can’t. Unpatched services, exposed injection points, disabled MFA on vendor-facing portals, and Internet of Things (IoT) devices with default credentials are all observable externally. They signal that a vendor’s commitment to security isn’t translating from design philosophy into actual deployment behavior.
How TITAN AI Operationalizes Secure by Design Vendor Assessment
TITAN Assess automates the security questionnaire and assessment process at scale. It maps questionnaire responses against observable security signals so that self-reported SbD commitments can be verified rather than blindly trusted. When a vendor claims to follow SbD principles, TITAN Assess gives your team the data to test that claim against real-world evidence.
TITAN Watch continuously scans vendor infrastructure from the outside in, surfacing signals indicating whether a vendor’s security practices hold up in production. Exposed services, degraded security scores, and unpatched vulnerabilities are indicators that secure design principles aren’t being maintained throughout the product lifecycle. If you need to prioritize vendor relationships by risk, TITAN Watch makes the SbD posture of every vendor in your ecosystem visible in real time — turning a design philosophy into a measurable, actionable signal.
Ready to see which vendors in your ecosystem actually follow secure by design principles? Book a demo with SecurityScorecard.
