Input validation hardening
We harden the server-side check of all incoming data: forms, parameters, file uploads, API — we check type, length, format and allowed values on the server, not just in the browser. To cut off incorrect and malicious input before it reaches the database, files or logic. Honestly upfront: input validation is a foundational layer that reduces the risk of injections and abuse, but it works TOGETHER WITH query parameterization and output escaping, not as a replacement for them.
Input validation hardening — overview
Input validation hardening is a review and reinforcement of how the server checks ALL incoming data: form fields, GET/POST parameters, headers, file uploads (type, size, content), API data. We check type, length, format, range and the list of allowed values — on the SERVER side (not trusting the browser). Honestly about the principle, this is key: client-side (browser) validation is a convenience for the user, but NOT security: it is easily bypassed by sending a request directly. So real protection is server-side validation only. Honestly about the combination: input validation reduces the risk of injections, XSS and logic abuse, but it is part of layered protection — it does NOT replace SQL query parameterization (753) and output escaping against XSS (752): the right way is when all layers work together. Honestly about the effect: less of the class of attacks via 'dirty' input, but not a guarantee that no vulnerability remains — that requires a code audit/scan. Honestly about discipline: validation must be maintained when adding new forms/fields, otherwise holes appear. Honestly about access: access to the code where data is received is needed. An important boundary: this is INPUT validation (what we accept), while OUTPUT protection (752) and DB parameterization (753) are adjacent separate layers. Picture this: instead of 'anything can be typed into a field and it goes into the database/logic as is' — incorrect and malicious input is cut off on the server. The base price starts from 15,000 ₽; it depends on the number of forms/endpoints.
Problems we solve
- Data is checked only in the browser — the check is easily bypassed directly.
- Anything can be typed into fields, and it goes into the database/logic.
- File uploads without type/size/content checks.
- No unified validation rules — each form does its own thing.
What's included in the Input validation hardening service
- An audit of all data-intake points (forms, parameters, API, uploads)
- Server-side check of type/length/format/allowed values
- Safe checking of file uploads (type/size/content)
- A unified approach to validation (not piecemeal)
- Pairing with parameterization (753) and escaping (752)
- Indicating boundaries (input validation — part of layered protection)
- Verification on real scenarios
- Handover and review with you
What you get
- Incorrect and malicious input is cut off on the server
- Lower risk of injections and logic abuse
- Unified, maintainable validation rules
- A foundational layer (full protection — in a stack of layers)
How the work goes: steps
- We find all data-intake points; collect access
- We implement server-side validation with a unified approach, link to layers 752/753
- We verify on real scenarios, review boundaries with you
Why PDV Expert
- Fixed price and timeline — no surprises on the invoice.
- Report and recommendations in plain language — clear without a technical background.
- In touch at every step and answering questions about the result.
FAQ
We already have a check in the form — is that not enough?
If the check is only in the browser (JavaScript) — it is not enough for security: it is easily bypassed by sending a request directly, skipping the page. Browser validation is a convenience for the user, while real protection is server-side validation. We will do exactly that, keeping the convenient client-side one too.
Will input validation replace protection against SQL injection and XSS?
No, these are layers of one defense. Validation cuts off 'dirty' input at entry, but proper DB protection is query parameterization (753), and XSS protection is output escaping (752). Honestly: all layers need to work together, not one instead of another.
After this, will there definitely be no vulnerabilities left?
That cannot be promised. Validation substantially reduces the class of input-based attacks, but 'no vulnerabilities' cannot be guaranteed — that requires a code audit/scan. And discipline must be maintained: when adding new forms, validation must be set up too.
About the provider
The «Input validation hardening» service is provided by PDV Expert — a team specialising in «Site quality». We work under contract and deliver a written report with recommendations.