CloudGuard WAF
  • Documentation Overview
  • What is CloudGuard WAF?
  • Getting started
    • Prepare key information
    • Log in to the Infinity Portal
    • Protect a Web Application / API
    • Deploy Enforcement Point
      • Gateway/Virtual Machine
        • AWS
          • Store Certificates in AWS
          • Store certificates on Gateway
        • Azure
          • Store Certificates in Azure
          • Store Certificates on Gateway
        • VMware
          • Store Certificates on Gateway
          • Configure networking in VMware Deployments
      • WAF as a Service
        • Certificates Managed by Check Point
        • Bring Your Own Certificate
      • Kubernetes Ingress
        • Kong Application Security
        • Istio Application Security
      • Docker
        • Single Docker
          • Deployment using 'docker' command
            • Store Certificates Locally on Docker
          • Deployment in Azure App Services
        • Dual Docker: NGINX/Kong/Envoy + Security Agent
      • Linux / NGINX / Kong
    • Monitor Events
  • Concepts
    • Gateways & Agents
    • Management & Automation
    • Security Practices
    • Contextual Machine Learning
  • Additional Security Engines
    • Anti-Bot
    • API Protection
      • API Discovery
      • Track API Discovery Learning
      • Enforce API Schema
    • File Security
    • Intrusion Prevention System (IPS)
    • Rate Limit
    • Snort Rules
  • SETUP INSTRUCTIONS
    • Setup Custom Rules and Exceptions
    • Setup Web User Response Pages
    • Setup Log Triggers
    • Setup Report Triggers
    • Setup Notification Triggers
    • Setup Behavior Upon Failure
    • Setup Agent Upgrade Schedule
  • HOW TO
    • Edit Web Application/API Settings
    • Edit Reverse Proxy Advanced Settings for a Web Asset
    • Protect an existing production site with CloudGuard WAF's Gateway
    • View Policy of all your Web Applications/APIs
    • Add Data Loss Prevention (DLP) rules
    • Configure Contextual Machine Learning for Best Accuracy
    • Track Agent Status
    • Track Learning and Move from Learn/Detect to Prevent
    • Rotate profile authentication token
    • Upgrade your Reverse Proxy when a Linux/NGINX agent is installed
    • Use Terraform to Manage CloudGuard WAF
    • Authorize Temporary Access for Check Point Support
    • Restrict Access to Backend Servers from CloudGuard WAF as a Service IPs Only
  • Troubleshooting
    • WAF Gateway / Virtual Machine
      • Azure
        • "Unable to find a tag containing the vault's name in the VMSS" Error
        • How To: Configure Key Vault for a Single Gateway
      • NGINX Error: Upstream Sent Too Big Header While Reading Response Header from Upstream
      • How To: Compare Between the Gateway's Certificate and the Upstream Certificate
    • Linux
      • SELinux: Checking Status and Disabling
    • WAF as a Service
      • Certificate Validation Failed: Adjusting CAA Record
      • How To: Redirect a Root Domain to a Subdomain Protected by WAF SaaS
      • How To: Extend Connection Timeout to Upstream
      • How To: Update Expired Certificates
  • references
    • Agent CLI
    • Management API
    • Event Query Language
    • Writing Snort Signatures
    • Events/Logs Schema
    • CVE-2022-3786 and CVE-2022-3602: OpenSSL X.509 Email Address Buffer Overflows (HIGH)
    • CVE-2025-1097, CVE-2025-1098, CVE-2025-24514, CVE-2025-1974: Ingress NGINX Controller RCE (Critical)
  • Resources
    • GitHub
    • Docker Hub
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  1. Troubleshooting
  2. WAF Gateway / Virtual Machine

NGINX Error: Upstream Sent Too Big Header While Reading Response Header from Upstream

PreviousHow To: Configure Key Vault for a Single GatewayNextHow To: Compare Between the Gateway's Certificate and the Upstream Certificate

Last updated 3 months ago

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NGINX is not able to read the header that is sent from the upstream as it is bigger than the configured size and the request is failing. In the NGINX error log (locating in: /var/log/nano_agent/rpmanager/nginx_log/error.log): "...*1435367 upstream sent too big header while reading response header from upstream ..."

The configured buffer that caches the responses is too small.

WHAT TO DO?

  1. Open the Infinity Portal

  2. Click on Cloud tab → Assets

  3. Navigate to the relevant asset and click on it.

  4. Click on Advanced... (Under the certificate section), and click on Additional Settings

  5. Mark V on the Additional Location Block Instruction checkbox and upload a .txt file with these lines in it: proxy_buffer_size 128k; proxy_buffers 4 256k; proxy_busy_buffers_size 256k;

  6. Click OK.

  7. Enforce the policy.