Common Security Vulnerabilities in Business Applications

Broken access control is when a system fails to properly restrict what a user can see or do to only what their role should permit — for example, changing a number in a web address and being able to view another customer's order because the system never checked whether that record actually belonged to the logged-in user. According to OWASP, the non-profit industry body that maintains the most widely referenced list of web application security risks, broken access control is the most common category found in real-world testing across the applications in its dataset (OWASP Top 10:2025).

Injection is when an application takes input from a user and, without properly checking it, treats part of that input as an instruction rather than as data — letting an attacker manipulate a database query or a command the application runs, rather than sending it the ordinary information the field expects. Security misconfiguration is broader: a setting left at an insecure default, an error message that reveals more about the system than it should, or a service left switched on that nobody actually uses — all three remain among the most common categories OWASP tracks in its 2025 Top 10 list.

Broken access control, in a business context, usually means one customer or employee account can see or change data that belongs to someone else — another customer's order history, another branch's sales figures, another employee's records. The business cost is typically a trust and compliance problem: a customer whose data was visible to a stranger, or a regulator asking hard questions about why.

Injection flaws can let an attacker extract, alter or delete data far beyond what the application's interface was ever designed to allow — a single vulnerable form becoming a path to an entire customer database. Security misconfiguration is often the quiet enabler behind both of the others: a default admin password never changed, a test environment left reachable from the public internet, or detailed error messages that hand an attacker a map of the system they are probing. Imagine a chartered-accountancy firm's client-facing document portal, built on custom software, where a search field passed customer input straight into a database query — a textbook injection risk that had nothing to do with how strong anyone's password policy was.

Prevention for these categories follows a consistent pattern, without needing deep technical detail to understand: check that every request actually belongs to the user making it, treat all user input as untrusted data rather than as trusted instructions, keep systems patched and their configurations deliberately reviewed rather than left at their installed defaults, and avoid revealing more information than necessary in error messages and logs.

Confirming these protections actually hold, rather than assuming they do, is where authorised testing earns its place — a vulnerability assessment or penetration test conducted with explicit permission and a defined, agreed scope, carried out by a party the business has vetted. This should never be attempted informally or without written authorisation, since even well-intentioned testing without permission can disrupt production systems or create legal exposure.

Not every finding from a review or a test carries equal urgency. A weakness reachable from the public internet, touching customer financial or personal data, deserves attention before a similar weakness that only an authenticated internal user could reach on a system with no sensitive data at all — exposure and impact together, not the category label alone, should drive the order fixes happen in.

A simple way to think about this: rank each finding by how easily it could be reached (public internet, internal network only, requires existing account) and what it would expose if reached (nothing sensitive, some business data, customer personal or financial data). The findings that are both easy to reach and expose sensitive data go first, regardless of how technically interesting a lower-priority finding might be.

These vulnerability categories are not a one-time list to check off — new features, new integrations and updated dependencies all reopen the same questions. A recurring review cycle, at an interval that matches how quickly the application actually changes, keeps this from becoming a problem that is only rediscovered after something has already gone wrong.

Tracking findings over time — not just fixing each one in isolation, but noticing if the same category keeps recurring across releases — often points to a process gap worth fixing at the source, such as a missing code review step or a testing stage that gets skipped under deadline pressure.