{"id":26781,"date":"2026-06-05T22:24:39","date_gmt":"2026-06-05T22:24:39","guid":{"rendered":"https:\/\/data-mammoth.com\/application-security\/"},"modified":"2026-06-05T22:50:38","modified_gmt":"2026-06-05T22:50:38","slug":"application-security","status":"publish","type":"page","link":"https:\/\/data-mammoth.com\/es\/application-security\/","title":{"rendered":"Application Security"},"content":{"rendered":"

Application security<\/strong> is no longer a box-ticking exercise – it is the difference between winning enterprise contracts and losing them. This is the story of how Data Mammoth helped a fast-growing fintech secure its payment platform before a single attacker, or a single enterprise auditor, could find a way in.<\/p>\n

The client<\/h2>\n

Our client was a UK-based fintech startup with around 40 employees, building a payment portal that businesses use to collect and reconcile card payments. They had strong product-market fit and a growing customer base – but they were also about to sign their first large enterprise customers, each of whom would put the platform through a rigorous security review before going live. A single serious vulnerability could sink those deals.<\/p>\n

The challenge<\/h2>\n

The team had grown quickly, and security had not kept pace with the code. There had been a near-miss months earlier when a customer reported seeing data that was not theirs – an incident that was patched in a hurry but never fully understood. With enterprise security questionnaires landing and a PCI-aligned audit on the horizon, the founders needed certainty: where were they exposed, how bad was it, and how fast could it be fixed?<\/p>\n

\"Application<\/p>\n

How we investigated<\/h2>\n

We started where every solid application security engagement should: with scope and context, not tools. Over an initial workshop we mapped the platform’s architecture, identified the highest-risk areas – authentication, payment flows, and anything touching cardholder data – and built a lightweight threat model so our testing focused on what actually mattered to the business.<\/p>\n

From there we ran a layered assessment:<\/p>\n

    \n
  • Grey-box penetration testing<\/strong> of the live application, aligned to the OWASP Top 10, using both authenticated and unauthenticated accounts.<\/li>\n
  • Static analysis (SAST)<\/strong> across the codebase to surface insecure patterns at scale.<\/li>\n
  • Manual secure code review<\/strong> of the authentication, session, and payment logic – the areas where automated tools routinely miss the most damaging flaws.<\/li>\n<\/ul>\n

    What we found<\/h2>\n

    The near-miss had not been a fluke. Our testing uncovered a small number of high-impact issues hiding in plain sight:<\/p>\n

      \n
    • An insecure direct object reference (IDOR)<\/strong> that let an authenticated user view another customer’s transactions by changing a single value in a request – the root cause of the earlier incident.<\/li>\n
    • Stored cross-site scripting (XSS)<\/strong> in the support-ticket feature, which could be used to hijack an administrator’s session.<\/li>\n
    • Weak token validation<\/strong> in the session layer that did not properly verify how authentication tokens were signed.<\/li>\n
    • An outdated third-party dependency<\/strong> carrying a publicly known, exploitable vulnerability.<\/li>\n<\/ul>\n

      How we fixed it<\/h2>\n

      Finding problems is the easy part. We worked directly with the client’s developers – pairing on fixes rather than throwing a report over the wall – to remediate every issue and, just as importantly, to make sure the same classes of bug could not return:<\/p>\n

        \n
      • Rebuilt access-control checks so every request is authorised against the logged-in user, closing the IDOR.<\/li>\n
      • Introduced consistent output encoding and input validation to eliminate the XSS.<\/li>\n
      • Hardened token signing and validation in the session layer.<\/li>\n
      • Upgraded the vulnerable dependency and added automated dependency scanning to the build.<\/li>\n
      • Added security checks into their CI pipeline, so risky code is now caught before it ships.<\/li>\n<\/ul>\n

        We then re-tested everything to confirm the fixes held under the same attacks that had succeeded before.<\/p>\n

        The results<\/h2>\n

        The retest came back clean on every previously identified issue. More importantly for the business:<\/p>\n

          \n
        • The platform passed its first enterprise security review without a single critical finding outstanding.<\/li>\n
        • The deal that depended on that review closed on schedule.<\/li>\n
        • The team now ships with security gates in place, turning a one-off audit into an ongoing standard.<\/li>\n<\/ul>\n

          Frequently asked questions<\/h2>\n

          What is application security?<\/h3>\n

          Application security is the practice of finding and fixing weaknesses in software – web portals, APIs, and mobile apps – before attackers can exploit them. It combines penetration testing, secure code review, and secure development practices so security is built in rather than bolted on.<\/p>\n

          How long does an application penetration test take?<\/h3>\n

          It depends on the size and complexity of the application, but a focused engagement on a single web platform typically runs from one to three weeks, including scoping, testing, reporting, and a retest of the fixes.<\/p>\n

          Will testing disrupt our live service?<\/h3>\n

          No. We scope every engagement carefully and, where needed, test against staging environments or during agreed windows so your customers never feel a thing.<\/p>\n

          Securing customer-facing software often goes hand in hand with building it well from the start – see how we approach custom web application development<\/a>, or read about our managed IT services<\/a>. Ready to find out where you stand? Talk to our security team<\/a>.<\/p>\n