Bot Management Configuration

Bot Management Configuration

Product Tiers

Note: Dashboard paths differ between old and new UI:

• New: Security > Settings > Filter "Bot traffic"
• Old: Security > Bots

Both UIs access same settings.

Bot Score Groupings (Pro/Business)

Pro/Business users see bot score groupings instead of granular 1-99 scores:

Enterprise plans get granular 1-99 scores for custom thresholds.

Bot Fight Mode (Free)

• Auto-blocks definite bots (score=1), excludes verified bots by default
• JavaScript Detections always enabled, no configuration options

Super Bot Fight Mode (Pro/Business)

Dashboard: Security > Bots > Configure
- Definitely automated: Block/Challenge
- Likely automated: Challenge/Allow  
- Verified bots: Allow (recommended)
- Static resource protection: ON (may block mail clients)
- JavaScript Detections: Optional

Bot Management for Enterprise

Dashboard: Security > Bots > Configure > Auto-updates: ON (recommended)

# Template 1: Block definite bots
(cf.bot_management.score eq 1 and not cf.bot_management.verified_bot and not cf.bot_management.static_resource)
Action: Block

# Template 2: Challenge likely bots
(cf.bot_management.score ge 2 and cf.bot_management.score le 29 and not cf.bot_management.verified_bot and not cf.bot_management.static_resource)
Action: Managed Challenge

JavaScript Detections Setup

Enable via Dashboard

Security > Bots > Configure Bot Management > JS Detections: ON

Update CSP: script-src 'self' /cdn-cgi/challenge-platform/;

Manual JS Injection (API)

<script>
function jsdOnload() {
  window.cloudflare.jsd.executeOnce({ callback: function(result) { console.log('JSD:', result); } });
}
</script>
<script src="/cdn-cgi/challenge-platform/scripts/jsd/api.js?onload=jsdOnload" async></script>

Use API for: Selective deployment on specific pages
Don't combine: Zone-wide toggle + manual injection

WAF Rules for JSD

# NEVER use on first page visit (needs HTML page first)
(not cf.bot_management.js_detection.passed and http.request.uri.path eq "/api/user/create" and http.request.method eq "POST" and not cf.bot_management.verified_bot)
Action: Managed Challenge (always use Managed Challenge, not Block)

Limitations

• First request won't have JSD data (needs HTML page first)
• Strips ETags from HTML responses
• Not supported with CSP via <meta> tags
• Websocket endpoints not supported
• Native mobile apps won't pass
• cf_clearance cookie: 15-minute lifespan, max 4096 bytes

__cf_bm Cookie

Cloudflare sets __cf_bm cookie to smooth bot scores across user sessions:

• Purpose: Reduces false positives from score volatility
• Scope: Per-domain, HTTP-only
• Lifespan: Session duration
• Privacy: No PII—only session classification
• Automatic: No configuration required

Bot scores for repeat visitors consider session history via this cookie.

Static Resource Protection

File Extensions: ico, jpg, png, jpeg, gif, css, js, tif, tiff, bmp, pict, webp, svg, svgz, class, jar, txt, csv, doc, docx, xls, xlsx, pdf, ps, pls, ppt, pptx, ttf, otf, woff, woff2, eot, eps, ejs, swf, torrent, midi, mid, m3u8, m4a, mp3, ogg, ts
Plus: /.well-known/ path (all files)

# Exclude static resources from bot rules
(cf.bot_management.score lt 30 and not cf.bot_management.static_resource)

WARNING: May block mail clients fetching static images

JA3/JA4 Fingerprinting (Enterprise)

# Block specific attack fingerprint
(cf.bot_management.ja3_hash eq "8b8e3d5e3e8b3d5e")

# Allow mobile app by fingerprint
(cf.bot_management.ja4 eq "your_mobile_app_fingerprint")

Only available for HTTPS/TLS traffic. Missing for Worker-routed traffic or HTTP requests.

Verified Bot Categories

# Allow search engines only
(cf.verified_bot_category eq "Search Engine Crawler")

# Block AI crawlers
(cf.verified_bot_category eq "AI Crawler")
Action: Block

# Or use dashboard: Security > Settings > Bot Management > Block AI Bots

Best Practices

• ML Auto-Updates: Enable on Enterprise for latest models
• Start with Managed Challenge: Test before blocking
• Always exclude verified bots: Use not cf.bot_management.verified_bot
• Exempt corporate proxies: For B2B traffic via cf.bot_management.corporate_proxy
• Use static resource exception: Improves performance, reduces overhead