ssti-testing

ssti-testing is a skill for Claude Code, Codex from xAmirHamza77/PenKit51. It costs 49 tokens per session (9,129 once invoked), scanned D, original, no licence file.

A security-testing skill for server-side template injection, a flaw where template input can make the server run unintended actions. It covers several template systems and investigates possible sandbox escapes and remote code execution.

In plain words
What is it for?
Use it to identify template engines, test for injection, and examine whether an issue could lead to escaping restrictions or running code on the server.
Why use it?
It helps find and assess a class of vulnerabilities that can be difficult to recognise across different template systems.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing.

Good fit Use it to identify template engines, test for injection, and examine whether an issue could lead to escaping restrictions or running code on the server.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/xamirhamza77/penkit51/ssti-testing
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add xAmirHamza77/PenKit51 --skill ssti-testing
Clone the repo
git clone --depth 1 https://github.com/xAmirHamza77/PenKit51

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for ssti-testing

README.md
[![agentmods](https://agentmods.dev/badge/skills/xamirhamza77/penkit51/ssti-testing/github.svg)](https://agentmods.dev/skills/xamirhamza77/penkit51/ssti-testing)
Your own site
<a href="https://agentmods.dev/skills/xamirhamza77/penkit51/ssti-testing"><img src="https://agentmods.dev/badge/skills/xamirhamza77/penkit51/ssti-testing/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for ssti-testing

Your own site · 80×15
<a href="https://agentmods.dev/skills/xamirhamza77/penkit51/ssti-testing"><img src="https://agentmods.dev/badge/skills/xamirhamza77/penkit51/ssti-testing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 9,129 The whole file, excluding the scripts and references it only reads on demand.
Security scan D 4 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00049 $0.09129
Opus 5 $0.00024 $0.04564
Sonnet 5 $0.00010 $0.01826
Haiku 4.5 $0.00005 $0.00913

Measured 9d ago against content hash 118b4a6dff51, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade D, and why

ssti-testing scanned grade D with 4 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Reaches for credential filesmediumPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

- Persistence: cron, scheduled task, systemd unit, `~/.ssh/authorized_keys`, web shell in webroot

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Encoded or obfuscated payloadmediumSupply chain

base64 or hex that is decoded and executed hides what actually runs from anyone reading the file.

- Python: `os.system`, `os.popen`, `subprocess.run`, `subprocess.Popen`, `__import__('os').system`

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Cloud metadata endpointmediumServer-side request forgery

One request to 169.254.169.254 can return temporary IAM credentials.

- Cloud metadata fetch (`http://169.254.169.254/latest/meta-data/`, `http://metadata.google.internal/`) — IAM tokens

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

Runs shell commandslowCapability

Expected in a hook, worth knowing in a rule or an instructions file.

The classic Python class walk — every object exposes its method-resolution-order, which leads to `object`, which exposes every subclass loaded in the interpreter, which includes things like `subprocess.Popen`:
skills/ssti-testing/SKILL.md · 568 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 9d ago First seen · 568 lines · 49 tokens per session scan D 118b4a6dff51

Subscribe to this mod's changes

ssti-testing is a skill published in the GitHub repository xAmirHamza77/PenKit51 (2 stars, last pushed 2mo ago), with no licence file. It adds 49 tokens to every session and 9,129 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it D with 4 findings (reaches for credential files, encoded or obfuscated payload, cloud metadata endpoint). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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