deadeye-guard

name	deadeye-guard
description	Security review of the current diff -- injection, secrets, authz, crypto, and vulnerable dependencies.
license	MIT

Deadeye Guard

Review ONLY the changed code for security exposures. Nothing else: lean- lens over-engineering is /deadeye-review's job, not this one.

This is the deep pass behind coder mode's live Edit/Write advisory: the advisory is a fast regex reminder on the text just written; this skill reads around the hunk, verifies before reporting, and runs real dependency auditors where they're installed.

Scope

Get the diff with git diff (or git diff --staged if the user says staged, or git diff <ref> for a named base). Read the changed hunks plus enough surrounding context to judge a trust boundary — more than /deadeye-review needs, since "is this input actually validated" often requires seeing the caller.

• Empty diff (nothing changed or staged): say so plainly and stop — do not substitute a different scope.
• Not a git repo: ask the user which files to review.
• Diff-scoped by design, not repo-wide — a whole-repo sweep would re-read everything into context for exposures that haven't changed; that's what native auditors and periodic CI scanning are for.

Verify before reporting

Before claiming a sanitizer, an authz check, or input validation is MISSING, grep for it OUTSIDE the diff — middleware, a decorator, a framework-level guard, a base class. An unguarded-looking handler whose auth actually lives in a router Use() call is a false positive, and one wrong finding erodes trust in all of them. Report only what you confirmed.

A deadeye: <shortcut>. ceiling: <limit>. upgrade: <trigger>. comment covering a hunk is a recorded DECISION, not a finding — someone already chose to ship that exposure with eyes open. Count it separately from what you flag; /deadeye-debt owns the ledger of those.

Dependency pass

Detect the ecosystem from the manifest touched in the diff (go.mod, package.json, requirements.txt/pyproject.toml, Cargo.toml, pom.xml/build.gradle), then run its native auditor if installed:

Ecosystem	Command
Go	govulncheck ./...
npm	npm audit --json
Python	pip-audit -f json (or osv-scanner -L requirements.txt)
Rust	cargo audit
any	osv-scanner -L <manifest> as a fallback

If the tool isn't installed, SAY SO and fall back to what coder mode's live advisory already used — the bundled superseded-package table and ~/.deadeye/osv-cache.json — rather than fabricating a CVE list. When a dependency is vulnerable or abandoned, report the fix in ladder order: stdlib or native first, a maintained sibling second, a version bump last — deleting the dependency is a fix too, and often the shortest one.

Format

One line per finding:

L<line>: <tag> <what reaches what>. <fix>.

Seven tags, use exactly these:

• inject: — untrusted input reaches SQL, a shell, a template, a path, or eval
• secret: — a credential literal, or a secret handled somewhere it can leak (logs, error messages, client-visible output)
• authz: — a decision or resource access with no confirmed permission check
• crypto: — hand-rolled or weak crypto (MD5/SHA1 for passwords, a non-CSPRNG for a token, TLS verification disabled)
• expose: — sensitive data returned/logged beyond what the caller needs
• dep: — a vulnerable or superseded dependency, from the pass above
• dos: — untrusted input sizes an allocation, an unbounded loop, or unbounded recursion → memory or CPU exhaustion. Cap it, or bound the input first

Rank by exploitability (reachable from untrusted input first). End with <N> exposures, <M> accepted. (accepted = the marked, decided-corners count from the verify step) — or, when nothing survives, exactly: Clean line of fire.

More than ~12 findings: keep the highest-exploitability ones and say how many lower-severity ones were omitted.

Examples

✅ L42: inject: name interpolated into a raw SQL string. Bind it as a query parameter. ✅ L88: authz: /admin/users has no role check in this diff or its router group. Add one, or confirm it's covered upstream. ✅ L15: dep: lodash 4.17.20 has an open OSV advisory (GHSA-p6mc-m468-83gg). 4.17.21 patches it, or drop it -- the two helpers used here are stdlib now. ✅ L120: crypto: password hashed with md5. Use bcrypt/scrypt/argon2 instead.

❌ "This endpoint might have some security considerations worth thinking about..." — hedging isn't a finding. Name the line, the reachable input, the fix.

Boundaries

• Findings are a LIST. Do not apply them unless asked.
• Never flag coder mode's one runnable check for deletion — lean code without its check is unfinished.
• Never fabricate a CVE, an advisory ID, or a fixed version you didn't actually see from a tool or the OSV cache.
• Lean-lens over-engineering (unnecessary abstraction, reinvented stdlib, a shorter form that does the same job) is OUT of scope here — that's /deadeye-review.