SaferSkills independently audited clash-skill-e9e863 (Agent Skill) and scored it 91/100 (green). The audit ran 55 deterministic rules across Security, Supply Chain, Maintenance, Transparency, and Community; it found 1 high-severity and 0 lower-severity findings. The full rule-by-rule trace and per-finding evidence are below. Free, methodology-open.
HIGHFenced code block that tells the agent to run a commandSS-SKILL-INJECT-FENCED-RUN-01 · Prompt injection · README.md
HIGH — a successful fenced-imperative injection runs attacker-supplied shell on the user's machine.
Why it matters
A fenced bash/python block in SKILL.md carries a natural-language imperative — "now run this", "execute the following command" — directing the agent to execute the fenced content. What looks like documentation becomes an executable payload the agent may run without ever asking you.
The exact value spotted
excerptREADME.md· markdown
76```bash
77npx [email protected] -t claude -y # persona / skills / style + defa