hunt-supabase

hunt-supabase is a skill for Claude Code, Codex from uphiago/recon-skills. It costs 133 tokens per session (5,136 once invoked), scanned B, original, MIT.

A security-testing guide for Supabase, a hosted backend service that provides databases, login, file storage, and APIs. It focuses on exposed data and incorrect Row Level Security rules, which control who can access each record.

In plain words
What is it for?
Use it to test Supabase REST tables, database functions, storage buckets, registration, login, public JavaScript bundles, and organization-based access controls.
Why use it?
It helps find applications where public keys, database policies, storage settings, or backend functions allow users to view or change another customer's data.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to test Supabase REST tables, database functions, storage buckets, registration, login, public JavaScript bundles, and organization-based access controls.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/uphiago/recon-skills/hunt-supabase
About the project

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.

uphiago/recon-skills · 1,251 stars · on GitHub · hiago.sh

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 uphiago/recon-skills --skill hunt-supabase
Clone the repo
git clone --depth 1 https://github.com/uphiago/recon-skills

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 hunt-supabase

README.md
[![agentmods](https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-supabase/github.svg)](https://agentmods.dev/skills/uphiago/recon-skills/hunt-supabase)
Your own site
<a href="https://agentmods.dev/skills/uphiago/recon-skills/hunt-supabase"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-supabase/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 hunt-supabase

Your own site · 80×15
<a href="https://agentmods.dev/skills/uphiago/recon-skills/hunt-supabase"><img src="https://agentmods.dev/badge/skills/uphiago/recon-skills/hunt-supabase.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 133 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 5,136 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 2 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 13 findings, up to high

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 →

  • high Privilege Escalation · line 50
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 52
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Privilege Escalation · line 53
    Code accesses credential files (SSH keys, AWS credentials, etc.). This could indicate credential theft attempts.
    Fix: Remove references to credential paths. Use environment variables or secrets managers. For docs, use placeholder paths (e.g., /path/to/config). Never load .env or token files in production code paths.
  • high Supply Chain · line 57
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 93
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 145
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 216
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 235
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • high Supply Chain · line 416
    Remote code is downloaded and executed. This bypasses code review and could introduce malicious code.
    Fix: Avoid downloading and executing remote scripts. Use trusted packages from PyPI/npm. If remote fetch is required, verify checksums and use HTTPS.
  • medium Data Exfiltration · line 145
    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.
  • medium Excessive Agency · line 192
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
  • medium Data Exfiltration · line 235
    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.
  • medium Data Exfiltration · line 256
    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.
How audits are shown
Origin original 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 $0.00133 $0.05136
Opus 5 $0.00067 $0.02568
Sonnet 5 $0.00027 $0.01027
Haiku 4.5 $0.00013 $0.00514

Measured 6d ago against content hash acdb8dcc0e41, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade B, and why

hunt-supabase scanned grade B 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 6d 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.

Downloads and executes remote codemediumSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET/manifest.json" | python3 -c "import sys, json; d = json.load(sys.stdin); print(d)" 2>/dev/null

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

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET" | grep -Eo 'src="[^"]*\.js"' | cut -d'"' -f2 | while read js; do
redteam/hunt-supabase/SKILL.md · 440 lines

How it starts

The opening of the file, as written. The whole thing — 440 lines — stays where its author put it; the contents beside it link to each section on GitHub.

HUNT-SUPABASE — Supabase Exploitation

Crown Jewel Targets

Supabase is the open-source Firebase alternative. It uses Row Level Security (RLS) for access control, but RLS policies are frequently misconfigured — especially in rapid-development stacks (Lovable.dev, Bolt.new, Cursor).

Highest-value findings:

  1. Public tables via anon key — REST API with anon key returns table data when RLS is disabled or policies are permissive. Critical.
  2. RLS bypass via organization_id — UPDATE operation checks user ownership but NOT organization_id -> cross-tenant data access. Critical.
  3. RPC functions returning global data — SECURITY DEFINER RPC functions that don't filter by auth.uid() -> all users' data. High.
  4. Storage buckets without RLS — Public file listing, upload, and download. High.
  5. Open signUp — Anyone can register and get a JWT. High.
  6. Multi-tenant enumeration — Same broken-RLS patterns across multiple apps built by the same developer. Medium.

Phase 1 — Find the Supabase Project

Supabase is identified by its URL format: https://[PROJECT_REF].supabase.co and anon key format: eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9... (JWT starting with eyJ)

1.1 Search in JS Bundles

# Download JS bundles and search for Supabase
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET" | grep -Eo 'src="[^"]*\.js"' | cut -d'"' -f2 | while read js; do
  curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET$js" -o "/tmp/$(basename $js)"
done

# Search for Supabase URL pattern
grep -rEn 'https://[a-z0-9-]+\.supabase\.co' /tmp/*.js
grep -rEn 'supabaseUrl|SUPABASE_URL|supabaseKey|SUPABASE_ANON_KEY' /tmp/*.js

# Search for Supabase JWT anon key
grep -rEn 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9\.[^[:space:]]+' /tmp/*.js

# Quick one-liner
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET" | grep -Eo 'https://[a-z0-9-]+\.supabase\.co'
curl --max-time 30 --connect-timeout 10 -sk "https://$TARGET" | grep -Eo '(?:supabaseUrl|SUPABASE_URL)[": ]+[^"'\''\s]+'

Read the full file on GitHub · 440 lines

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. 6d ago First seen · 440 lines · 133 tokens per session scan B acdb8dcc0e41

Subscribe to this mod's changes

hunt-supabase is a skill published in the GitHub repository uphiago/recon-skills (1,251 stars, last pushed 8d ago), licensed MIT. It adds 133 tokens to every session and 5,136 once invoked, about $0.0007 per session on Opus 5. A static security scan graded it B with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.

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