# Insufficient Business Logic Input Validation

> Detects missing or inadequate server-side validation of business-critical fields that could be manipulated.

- Skill: `zakirkun/insufficient-business-logic-input-validation` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add zakirkun/insufficient-business-logic-input-validation`
- Raw SKILL.md: https://api.skillmd.com/api/skills/zakirkun/insufficient-business-logic-input-validation/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools
- Author: zakirkun (https://skillmd.com/u/zakirkun)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/zakirkun/insufficient-business-logic-input-validation

---


# Insufficient Business Logic Input Validation

## Overview
Beyond injection and type checking, business logic requires semantic validation:
- Age/date fields must be realistic (no future birthdays for adults)
- Email domain validation (company domains for B2B)
- Geolocation consistency (billing address matches IP country)
- Field length limits on free-text fields to prevent DoS

## Remediation
- Implement domain-specific validation for each business field
- Define and enforce explicit validation rules at the controller layer
- Use validation libraries with schema definitions