Raven Zero Day Fixing

Raven — 0-Day Fixing

This skill is Raven's remediation layer. It turns a confirmed root cause into an applied patch or a verified rollback. It does NOT investigate (use raven-zero-day-investigator) and it does NOT decide policy (use raven-zero-day-auto-prevent). Every patch passes through the approval gate and at least one verifier oracle before it is applied.

When to use

Trigger when the user asks any of:

• "Fix / patch CVE-YYYY-NNNNN in <repo>"
• "Generate a fix for this confirmed finding"
• "Virtual-patch this at the WAF / sidecar layer"
• "Rollback this unsafe deployment"
• "Apply remediation for <finding>"

Do not trigger for: pre-confirmation speculation (use raven-zero-day-investigator first), routine dependency bumps (handle outside Raven), or any patch without a confirmed root cause record.

Inputs

Required:

1. Confirmed finding — root-cause record from raven-zero-day-investigator OR a validated finding from raven-zero-day-hunter. The record MUST include cwe, location, d3fend_techniques, and validator evidence.
2. Fix mode — one of: source-patch, virtual-patch, config-harden, rollback
3. Verification depth — unit-tests, unit-plus-static, unit-plus-static-plus-fuzz, formal (last is Solana / EVM only)

Optional:

• Approval mode — manual by default for source-patch and rollback, smart allowed for virtual-patch and config-harden
• Time budget — wall-clock cap

Pipeline — six mandatory stages

Stage 1 — Finding intake (𝒯-grounded)

1. Validate the finding record's schema; reject if missing CWE, location, or D3FEND ids.
2. Confirm the validator evidence path still exists and re-run the validator one more time. If the issue no longer reproduces, the skill aborts with already_fixed_or_drift — patching a non-issue is forbidden.
3. Resolve every D3FEND technique id in the finding via raven.d3fend.api.lookup_technique. Reject unresolved ids.

Stage 2 — Fix-mode routing

The skill MUST pick exactly one mode. Multi-mode fixes are decomposed into separate runs.

Stage 3 — Patch generation (𝓛-scored, 𝒯-bound)

For source-patch:

1. raven/mitigation/remediation_engine.py emits one or more candidate patches as unified diffs. The engine consults the finding's CWE, the local code style, and any pinned dependencies.
2. Each candidate MUST be regex-validated and shlex-quoted (the engine's existing safety property) — the skill does not write shell-strings.
3. The LLM may rank candidates but MUST NOT author them outside the engine. If the engine cannot produce a candidate, the skill emits no_engine_candidate and falls back to virtual-patch if eligible, otherwise stops.

For virtual-patch:

1. Generate a Nuclei template / WAF rule from the finding's evidence features.
2. The template MUST be reviewable as plain text and MUST be defensive only (block / log, never exploit).

For config-harden:

1. Emit a diff against the affected config file (e.g. AppArmor profile, nginx config, sysctl entry).

For rollback:

1. Look up the most recent good checkpoint via the restore/ subsystem.
2. Confirm the checkpoint's hash matches its recorded value.

Stage 4 — Pre-application verification (𝒯-grounded, mandatory)

For source-patch:

1. Apply the patch to a sandboxed branch / worktree.
2. Run the project's test suite. Fail if any test regresses.
3. Re-run ares.py or code_flow_scanner.py and confirm the finding no longer reproduces.
4. If verification depth includes fuzz, run a short fuzz session and require no new crashes.
5. If verification depth is formal and the target is Solana / EVM, run the formal-verification stub in raven/ml/vulnerability_validator.py against the patched program.

For virtual-patch:

1. Stage the rule in a shadow mode against replayed traffic.
2. Confirm zero false positives on a known-good replay batch and ≥ 1 true positive on the exploit payload.

For config-harden:

1. Parse-check the new config (syntax).
2. Apply in a staging environment if available; confirm the affected service still starts and serves health checks.

For rollback:

1. Verify the checkpoint integrity hash before any state mutation.
2. Dry-run the rollback against an isolated copy if the restore/ subsystem supports it.

If any verifier fails, the patch is NOT promoted. The skill emits verification_failed and exits.

Stage 5 — Approval gate

Route the verified candidate through raven/approval/gate.py. The skill MUST supply:

• The finding record
• The unified diff (or rule / config / checkpoint reference)
• The verifier results (test counts, oracle outputs, fuzz session summary)
• The D3FEND id this fix claims to implement

raven/approval/smart.py may auto-approve virtual-patch and config-harden actions that pass all verifiers. source-patch and rollback always require manual approval unless the user explicitly configured otherwise in policy via raven-zero-day-auto-prevent.

UNRECOVERABLE_BLOCKLIST patterns are hard-rejected.

Stage 6 — Apply and post-verify (𝒯-grounded)

After approval, apply the change through the appropriate module:

• source-patch → remediation_engine.apply(...) — note this is the same module that owns the existing patch-apply path
• virtual-patch → install WAF/sidecar rule via the configured provider's API
• config-harden → response_orchestrator.execute_config_change(...)
• rollback → invoke the restore/ subsystem's primitive matching the D3FEND id (D3-RS, D3-RC, etc.)

After application, run a final verifier pass on the live target. If post-verify fails:

• For source-patch / config-harden / rollback — initiate the restore/ subsystem's automatic recovery (return to pre-change state) and escalate.
• For virtual-patch — disable the rule and escalate.

CDP contract — quick check before applying

assert finding.confirmed is True
assert finding.cwe is not None
assert all d3fend_id in fix.d3fend_techniques resolve through ontology
assert pre_application_verifier_results.all_passed is True
assert approval_gate_decision == "approve"
assert at least one 𝒯 verifier oracle was invoked

Any failed assertion blocks the apply step.

Output contract

# Raven 0-Day Fix — <finding_id>

## Finding reference
- CWE: <id>
- Location: <file:lines or symbol or address>
- Validator evidence: <path>
- D3FEND tags on fix: <id list>

## Fix mode
- Mode: <source-patch|virtual-patch|config-harden|rollback>
- Generator module: <module>
- Candidate count: <n>
- Selected candidate: <id>

## Pre-application verification
| Verifier | Result | Detail |
|----------|--------|--------|
| Unit tests | pass / fail (<n>) | <summary> |
| ares.py re-run | not-reproduced / reproduced | <path> |
| code_flow_scanner | clean / hit | <path> |
| fuzz session | no-crash / crash (<n>) | <wall-clock> |
| formal | proved / counterexample | <path> |

## Approval
- Mode: <smart|manual>
- Decision: <approve|deny|escalate>
- Reason: <reason>

## Apply
- Wall-clock: <s>
- Side-effect handle: <pid / rule_id / commit_sha / checkpoint_id>

## Post-verification
| Check | Result |
|-------|--------|
| Live re-run | not-reproduced |
| Service health | green |

## Reproducibility kit
- Patch diff: <path>
- Verifier traces: <path>
- Commit: <sha>
- Audit record: <id>

Refusal rules

1. Refuse to apply any patch without re-running the validator and confirming the issue still reproduces in Stage 1.
2. Refuse to apply any patch that regresses the test suite.
3. Refuse to apply a source-patch or rollback in smart mode unless an active raven-zero-day-auto-prevent policy explicitly allows it.
4. Refuse to bypass the approval gate.
5. Refuse to apply without a D3FEND id tag — every fix MUST cite the Harden or Restore technique it implements.
6. Refuse to ship a virtual patch that has zero true positives in shadow mode.
7. Refuse rollback without checkpoint integrity verification.

Related skills

• raven-zero-day-investigator — upstream producer of confirmed findings.
• raven-zero-day-defend — sibling skill that stages the same actions before they execute.
• raven-zero-day-auto-prevent — invokes this skill when policy authorizes automatic fixes.
• restore/ subsystem — owns the rollback mode primitives (restore-subsystem-spec).
• D3FEND OWL integration (raven/d3fend/) — source of every Harden / Restore id on every fix (D3FEND home).