Tests web application email functionality (contact forms, password reset, newsletter subscriptions) for CRLF/SMTP header injection using Burp Suite and OWASP ZAP, checking whether attackers can inject headers, modify recipients, or abuse forms for spam relay. Use when testing any user-input-driven email-sending feature during a penetration test.
Install
npx skills add mukul975/Anthropic-Cybersecurity-Skills --skill testing-for-email-header-injectionnpx skills add mukul975/Anthropic-Cybersecurity-Skills --skill testing-for-email-header-injection -a claude-code -gnpx skills add mukul975/Anthropic-Cybersecurity-Skills --skill testing-for-email-header-injection -a codex -ggemini skills install https://github.com/mukul975/Anthropic-Cybersecurity-Skills.git --path skills/testing-for-email-header-injectiongh skill install mukul975/Anthropic-Cybersecurity-Skills testing-for-email-header-injectiongit clone --depth 1 https://github.com/mukul975/Anthropic-Cybersecurity-Skills /tmp/mukul975__Anthropic-Cybersecurity-Skills
mkdir -p ~/.claude/skills ~/.agents/skills
cp -R /tmp/mukul975__Anthropic-Cybersecurity-Skills/skills/testing-for-email-header-injection ~/.claude/skills/testing-for-email-header-injection # Claude Code
cp -R /tmp/mukul975__Anthropic-Cybersecurity-Skills/skills/testing-for-email-header-injection ~/.agents/skills/testing-for-email-header-injection # Codex, Cursor, Gemini CLI, Copilot, OpenCode