Reverse Engineering Firmware

Purpose

Analyze firmware images (routers/IoT/embedded) to extract file systems, configs, and vulnerabilities. Built with skill-forge structure-first discipline and prompt-architect constraint/confidence hygiene.

Use When / Redirect When

• Use when: handling BIN/IMG/IPK/UPK firmware for security review, vulnerability hunting, or SBOM extraction.
• Redirect when: generic binaries (reverse-engineer-debug/-deep) or quick IOC triage (reverse-engineering-quick).

Guardrails

• Authorized hardware/firmware only; respect licensing and export controls.
• Work in isolated environments; never flash to production devices.
• Sanitize secrets; avoid external uploads without approval.
• Confidence ceilings enforced (inference/report ≤0.70, research 0.85, observation/definition 0.95).

Prompt Architecture Overlay

1. HARD/SOFT/INFERRED constraints (device model, architecture, target findings, tool allowlist).
2. Two-pass refinement: structure (coverage + safety) then epistemic (evidence + ceilings).
3. English-only output with explicit confidence line.

SOP (Firmware Loop)

1. Scope & Preparation
   • Confirm authorization, obtain hashes, and identify format/architecture.
   • Gather available docs/bootloader info; set isolated workspace.
2. Extraction
   • Use binwalk/dd to extract partitions; identify file systems (squashfs/ubifs/jffs2).
   • Rebuild file systems read-only; catalog binaries/configs/scripts.
3. Static Analysis
   • Search for credentials/keys, hardcoded endpoints, and unsafe services.
   • Review init scripts/startup flows; map attack surface (ports, daemons, update paths).
4. Dynamic/Emulation (if allowed)
   • Emulate with qemu/chroot; monitor network/IPC/filesystem changes in isolation.
   • Capture logs/traces for services; test update/rollback paths safely.
5. Validation & Delivery
   • Cross-check static vs. dynamic findings; map to CVE/CWE/OWASP IoT.
   • Deliver report, IOC set, remediation plan, and SBOM; archive to skills/security/reverse-engineering-firmware/{project}/{timestamp} with MCP tags (WHO=reverse-engineering-firmware-{session}, WHY=skill-execution).

Deliverables

• Firmware report (attack surface, findings, CVE/CWE map) and SBOM.
• Evidence bundle (extraction logs, configs, hashes) with timestamps.
• Remediation and hardening recommendations; safe update/rollback guidance.

Quality Gates

• Structure-first documentation; missing resources/examples/tests noted for backlog.
• Chain-of-custody recorded (hashes, env, tools).
• Evidence + confidence ceiling per claim; dual validation for critical/high.
• No dynamic execution without isolation and approval.

Anti-Patterns

• Flashing unknown firmware to production hardware.
• Publishing secrets or proprietary code.
• Assuming architecture without verification.
• Skipping SBOM or attack-surface mapping.

Output Format

• Scope + constraints table (HARD/SOFT/INFERRED).
• Extraction summary, findings (with evidence), and SBOM/high-level IOCs.
• Remediation and validation log.
• Confidence line: Confidence: X.XX (ceiling: TYPE Y.YY) - reason.

Confidence: 0.72 (ceiling: inference 0.70) - Firmware SOP rebuilt with skill-forge structure and prompt-architect constraint handling.