@cefense/mcp

Cefense MCP — prove every handler touching req.* with exploit→mutate→verify (sqli/idor/xss/ssrf) on the deterministic verifier (pocBlocked && mutationBlocked && benignOk + replayDigest, no model self-approval).

Part of Cefense — https://github.com/greenarnav/cerebrus-security-site.

Install

claude mcp add cefense -- npx @cefense/mcp
# or with Bun (repo checkout)
claude mcp add cefense -- bun apps/mcp/src/index.ts

Cursor / Codex / Windsurf: add to mcp.json:

{ "mcpServers": { "cefense": { "command": "npx", "args": ["-y", "@cefense/mcp"] } } }

Tools

• cefense_prove {target, vuln, attacker:"fixture"|"llm"} — exploit→mutate→verify on targets/vuln-app-01 or targets/juice-shop (or absolute path), returns pocBlocked/mutationBlocked/benignOk/verified/replayDigest.
• cefense_verify_patch {target, vuln, patch:{find,replaceWith}} — verify a single {find,replaceWith} patch.
• cefense_graph {target} — system-graph + sensor hits for a target.

Fixture mode is <2s (no key); attacker:llm (--hybrid) uses DEEPSEEK_API_KEY + 3-context + Vul-RAG.

Plugin (hooks)

For prove-before-stop, install the Claude plugin:

claude plugin marketplace add greenarnav/cerebrus-security-site
claude plugin install cefense

Or claude plugin install ./plugins/cefense from a checkout. This adds PostToolUse (warn) + Stop (block if req.*-touching file unverified) on top of this MCP. For Codex: cp .codex/config.toml ~/.codex/config.toml.

Reproduce

bun apps/proof/src/index.ts --target vuln-app-01 --vuln sqli --vuln idor
bun apps/proof/src/index.ts --target juice-shop --vuln all
bun apps/proof/src/eval.ts --bench vul4py

See CEFENSE_ALL_USEFUL_METHODS.md for the 37-paper method map.