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Mitm Find Idor

Organization
instavm
mitm-find-idor

Find IDOR (Insecure Direct Object Reference) vulnerabilities in captured traffic. Use when user asks about authorization issues, sequential IDs, or accessing other users' data.

Overview

Publisherinstavm
Repositorysecurity-skills
Skill namemitm-find-idor
Stars
88
Forks
12
Bundled files
Instructions only
Links
  • Markdown instructions

    A SKILL.md file the model loads on demand, so it only costs tokens when a request actually matches.

  • Works with any LLM

    AI skills are plain Markdown, not provider-specific code, so this works with GPT, Claude, Gemini, Grok, or a local model.

  • Self-contained

    Everything the model needs lives in the instructions — no extra files to sync.

  • Open source

    Published by instavm on GitHub. Read the source before you install it.

Installation

Install the Mitm Find Idor AI skill in TypingMind to use it with any LLM, or drop it into another agent that reads SKILL.md.

1

Install in TypingMind

TypingMind installs a skill straight from its GitHub folder — it reads SKILL.md, bundles the resource files, and stores the result locally.

  1. Open the app and go to Plugins → Skills.
  2. Choose "Install from GitHub".
  3. Paste the skill folder URL below and confirm.
    https://github.com/instavm/security-skills/tree/main/skills/mitm-find-idor
  4. Enable the skill in any chat where you want it available.
Plugins → Skills → Add skill → From GitHub URL, then paste the folder URL and press Continue.
2

Install in another agent

Any agent that reads the Agent Skills format can use this skill — copy the folder into that agent's skills directory.

Claude Code — .claude/skills
git clone --depth 1 https://github.com/instavm/security-skills.git /tmp/security-skills
mkdir -p .claude/skills
cp -r /tmp/security-skills/skills/mitm-find-idor .claude/skills/mitm-find-idor
Restart Claude Code after copying so it picks up the new skill.

Use it in TypingMind

Enable Mitm Find Idor in any TypingMind chat and the model takes it from there. Its name and description sit in the system prompt, and the moment a request matches, the model loads the full instructions itself — you never invoke it by hand, and it costs no tokens until it is actually used.

The model loads Mitm Find Idor on its own as soon as a request matches it.

Works with any AI model

AI skills are plain Markdown instructions rather than provider-specific code, so Mitm Find Idor is not tied to the model it was written for. Install it once in TypingMind and use it with GPT-5, Claude, Gemini, Grok, DeepSeek, Mistral, Llama, or a local model you run yourself — all on your own API keys.

  • Loaded only when it is needed

    The system prompt carries just the name and description. The instructions are fetched on the first matching request, so an idle skill costs nothing.

  • Switch models mid-chat

    Because the skill is instructions rather than code, changing model does not break it — the next model reads the same SKILL.md.

Skill instructions

This is the SKILL.md content the model loads. Read it before installing — a skill is instructions your model will follow.

Find IDOR Vulnerabilities

Analyze the mitmproxy dump (log.txt) for IDOR vulnerabilities for: $ARGUMENTS

Requires: log.txt in the current directory. If it's missing, capture traffic first:

bash
mitmdump --set flow_detail=3 2>&1 | tee log.txt

High-Value IDOR Patterns (from 132 real HackerOne bounty reports)

1. User/Account Object References

user_id, userId, user-id, uid, account_id, accountId
customer_id, customerId, member_id, memberId
profile_id, owner_id, creator_id, author_id

Real example: https://zomato.com/gold/payment-success?subscription_id=XXX&user_id=YYY

2. Resource Object References

order_id, orderId, booking_id, bookingId, reservation_id
transaction_id, txn_id, payment_id, invoice_id
document_id, doc_id, file_id, attachment_id
report_id, ticket_id, case_id, issue_id

Real example: /api/shopify/orders/{order_id} - change order_id to access other orders

3. Organizational Object References

project_id, projectId, team_id, teamId, group_id, groupId
workspace_id, org_id, organization_id, company_id
board_id, channel_id, room_id, space_id

Real example: PUT /boards/{board_id}.json - GitLab private project label access

4. Content Object References

media_code, media_id, image_id, video_id, asset_id
post_id, postId, comment_id, message_id, thread_id
article_id, content_id, item_id, entry_id

Real example: media_code=2013124 - sequential IDs expose other users' media

5. Session/Token References (High Impact)

session_id, sessionId, subscription_id, subscriptionId
card_id, cardId, fuel_card_id, membership_id
api_key_id, token_id, credential_id

Real example: activateFuelCard?id=XXX - Uber driver UUID enumeration

ID Encoding Patterns to Decode

PatternExampleDecode Method
Base64 numericMTIzNDU2echo MTIzNDU2 | base64 -d → 123456
Hex0x1E240Convert to decimal → 123456
UUID v1Contains timestampExtract timestamp component
Short hasha1b2c3May be truncated MD5 of sequential
Padded000012345Strip padding, increment

Where to Find IDORs

URL Path Parameters (Most Common)

/api/v1/users/{id}/profile
/api/v1/orders/{id}/details
/api/v1/documents/{id}/download
/campaign-manager-api/accounts/{id}

Query Parameters

?user_id=12345&action=view
?subscription_id=XXX&user_id=YYY
?media_code=2013124

Request Body (JSON/Form)

json
{"user_id": 12345, "action": "delete"}
{"board": {"id": 857058, "labels": [{"id": 123}]}}

Headers (Rare but High Impact)

X-User-Id: 12345
X-Account-Id: 67890

Severity Rating

Access TypeSeverityExample
Read other users' PIICRITICALView email, phone, address
Modify other users' dataHIGHEdit profile, delete content
Access other users' orders/transactionsHIGHView order history, payment info
Read other users' private contentMEDIUMView private posts, documents
Enumerate user existenceLOWConfirm if user_id exists
Access public-ish dataINFOView subscription dates

Testing Methodology

Step 1: Identify Candidate Parameters

Search for ID patterns in traffic:

bash
grep -iE '(user|account|order|session|subscription|member|card|document|file|project|team|group)[-_]?id' log.txt

Step 2: Check for Sequential/Predictable IDs

bash
# Extract numeric IDs and check if sequential
grep -oE 'id[=:]["'\'']?[0-9]+' log.txt | sort -u

Step 3: Test Authorization

bash
# Test with ID ± 1
curl -H "Cookie: victim_session" "https://target.com/api/resource/12345"
curl -H "Cookie: victim_session" "https://target.com/api/resource/12344"  # Another user's

Step 4: Verify Impact

  • Does response contain different user's data?
  • Can you perform actions (edit/delete) on other user's resources?
  • What sensitive fields are exposed?

Output Format

For each finding report:

## IDOR Finding: [Brief Description]

**Endpoint**: `METHOD https://target.com/path`
**Parameter**: `param_name` in [path|query|body]
**ID Type**: [Sequential|Base64|UUID|Hash]
**Current Value**: `12345`
**Severity**: [CRITICAL|HIGH|MEDIUM|LOW]

**Evidence**:
[Show request/response snippets]

**Impact**:
- What data is exposed
- What actions can be performed

**Test Command**:
curl -X METHOD 'https://target.com/...' -H 'Cookie: ...'

**Remediation**:
- Implement proper authorization checks
- Use indirect references (mapping table)
- Validate user owns the resource

False Positives to Ignore

  • Analytics/tracking endpoints (write-only, no data returned)
  • Public content IDs (movie IDs, product catalog)
  • Resource IDs that return same data regardless of auth
  • IDs that require valid session AND return 403 for wrong user

Frequently asked questions

What does the Mitm Find Idor AI skill do?

Find IDOR (Insecure Direct Object Reference) vulnerabilities in captured traffic. Use when user asks about authorization issues, sequential IDs, or accessing other users' data.

Why use Mitm Find Idor on TypingMind?

Because you install it once and use it with any model. Mitm Find Idor is plain Markdown rather than provider-specific code, so the same skill runs on GPT-5, Claude, Gemini, Grok, or a local model — and you can switch model mid-chat without it breaking. TypingMind runs on your own API keys, so you pay providers directly instead of a per-seat subscription, and your skills and chats stay in your own storage.

How do I install Mitm Find Idor in TypingMind?

Open Plugins → Skills → Install from GitHub in TypingMind and paste https://github.com/instavm/security-skills/tree/main/skills/mitm-find-idor. TypingMind reads its SKILL.md and installs it as a skill you can enable per chat.

Which AI models can use Mitm Find Idor?

Any model you connect in TypingMind. AI skills are plain Markdown instructions rather than provider-specific code, so GPT, Claude, Gemini, Grok, and local models can all load this skill when a request matches it.

How many AI models can I use with Mitm Find Idor?

As many as you like. As long as a model supports skills, you can use Mitm Find Idor with it — GPT, Claude, Gemini, Grok, DeepSeek, Mistral, Llama and more — all on TypingMind with your own API keys.

Is the Mitm Find Idor AI skill free?

It is published on GitHub by instavm. Check the repository for licensing terms. You only pay your own AI provider for the tokens you use.

What are AI skills?

An AI skill is a reusable instruction bundle that teaches an AI model how to do one specific task. It follows the open Agent Skills format: a SKILL.md file with a name and description, plus any scripts, templates or reference files the model may need. The model reads the instructions only when your request matches the skill, so an installed skill costs nothing until it is used.

How are AI skills different from plugins or MCP servers?

A plugin or MCP server gives a model new tools to call — code that runs somewhere and returns a result. An AI skill gives the model knowledge and process instead: how to approach a task, which steps to follow, what good output looks like. Skills are plain Markdown, so they need no server, no API key and no runtime, and they work with any model.

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