planifest Security Secure Coding
Overview
Use this skill to prevent introducing exploitable code patterns and to enforce explicit security invariants during implementation.
Scope Boundaries
- New endpoints, parsers, deserializers, or command execution paths are added.
- Sensitive data handling or trust-boundary crossing logic changes.
- High-risk dependency or framework behavior needs secure usage decisions.
Templates And Assets
- Secure coding review checklist:
assets/secure-coding-review-checklist.md
Inputs To Gather
- Trust boundaries and untrusted input entry points.
- Sensitive data flows and storage/transmission requirements.
- Language/framework-specific risk patterns.
- Existing test coverage and security tooling signals.
Deliverables
- Security invariants for the changed code path.
- Mitigation mapping for relevant threat classes.
- Targeted secure coding checks and tests.
- Residual risk notes for deferred hardening work.
Workflow
- Identify attack surfaces for the change (input parsing, file/network access, auth context, templating).
- Run checklist from
assets/secure-coding-review-checklist.md. - Apply allowlist validation and context-appropriate encoding/sanitization at boundaries.
- Remove or harden dangerous patterns (shell concatenation, unsafe deserialization, path traversal gaps, SSRF primitives).
- Enforce explicit authorization checks in server-side handlers for sensitive operations.
- Protect secrets and PII in logs, errors, and telemetry outputs.
- Add or update negative tests for malicious payload classes.
- Verify dependencies and transitive packages for known critical vulnerabilities.
Quality Standard
- Security-relevant assumptions are explicit in code and tests.
- Error paths fail closed for sensitive operations.
- No sensitive data leaks through logs or debug output.
- High-risk operations are wrapped with deliberate validation and policy checks.
Failure Conditions
- Stop when trust-boundary validation is missing or implicit.
- Stop when privileged operations execute without explicit authorization checks.
- Escalate when unresolved critical vulnerabilities remain in production-bound paths.