mitm-find-idor

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

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:

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

Pattern	Example	Decode Method
Base64 numeric	MTIzNDU2	echo MTIzNDU2 | base64 -d → 123456
Hex	0x1E240	Convert to decimal → 123456
UUID v1	Contains timestamp	Extract timestamp component
Short hash	a1b2c3	May be truncated MD5 of sequential
Padded	000012345	Strip 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)

{"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 Type	Severity	Example
Read other users' PII	CRITICAL	View email, phone, address
Modify other users' data	HIGH	Edit profile, delete content
Access other users' orders/transactions	HIGH	View order history, payment info
Read other users' private content	MEDIUM	View private posts, documents
Enumerate user existence	LOW	Confirm if user_id exists
Access public-ish data	INFO	View subscription dates

Testing Methodology

Step 1: Identify Candidate Parameters

Search for ID patterns in traffic:

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

Step 2: Check for Sequential/Predictable IDs

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

Step 3: Test Authorization

# 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