ssti

name: ssti description: Hunt server-side template injection across Jinja2/Twig/Freemarker/Velocity/Handlebars and validate progression from expression injection to code execution. metadata: subdomain: web-exploitation when_to_use: "ssti server side template injection jinja2 twig freemarker velocity handlebars expression code execution"

SSTI Playbook

High-signal checks

• Look for template rendering with user input in render_template_string, Template(...), twig->createTemplate, Freemarker Template.process.
• Confirm user-controlled payload reaches a template context key or template source string.

Fast probes

• Jinja2: {{7*7}}, {{config}}, {{request}}
• Twig: {{7*7}}, {{_self}}
• Freemarker: ${7*7}
• Velocity: #set($x=7*7)$x

Escalation path

1. Detect expression evaluation.
2. Enumerate available objects and filters.
3. Attempt file read / env leak.
4. Attempt command execution via framework-specific gadget chain.

Validation

Use validate_finding with a positive execution signal and a benign negative control.