Request Body Inspection is enabled in Application Gateway WAF

Overview

Azure Application Gateway Web Application Firewall (WAF) provides centralized protection for web applications against common exploits and vulnerabilities at the regional level. Request body inspection is a critical capability that allows the WAF to analyze the content of HTTP POST, PUT, and PATCH request bodies for malicious patterns. When request body inspection is disabled, threat actors can craft attacks that embed malicious SQL statements, scripts, or command injection payloads within form submissions, API calls, or file uploads that bypass all WAF rule evaluation. This creates a direct path for exploitation where threat actors gain initial access through unprotected application endpoints, execute arbitrary commands or queries against backend databases through SQL injection, exfiltrate sensitive data including credentials and customer information, establish persistence by modifying application data or injecting backdoors, and pivot to internal systems through compromised application server credentials. The WAF’s managed rule sets, including OWASP Core Rule Set and Microsoft’s Bot Manager rules, cannot evaluate threats they cannot see; disabling request body inspection renders these protections ineffective against body-based attack vectors that represent the majority of modern web application attacks.

Remediation

Overview of WAF capabilities on Application Gateway including request body inspection

• What is Azure Web Application Firewall on Azure Application Gateway?

Guidance on creating and configuring WAF policies including request body inspection settings

• Create Web Application Firewall policies for Application Gateway

FAQ and best practices for tuning WAF including request body inspection limits

• Tuning Web Application Firewall for Azure Application Gateway

Run it

The check runs as part of the whole assessment, with the ZeroTrustAssessment module installed:

Install-Module ZeroTrustAssessment -Scope CurrentUser
Connect-Maester
Invoke-Maester -Pack ZTA -SkipBuiltIn

Leave out -SkipBuiltIn to run Maester’s own checks in the same run.

About this check

Severity	High
Effort to fix	Low
Impact on users	Low
Pillar	Network
Category	Azure Network Security
Product	Azure
Feature	Network security
Area	Infrastructure hardening
ATT&CK	T1190 Exploit Public-Facing Application
Licence	Azure WAF
Tenant	Workforce

Product, feature, area and ATT&CK are Maester’s: the assessment does not record them, so Maester keeps them in the pack’s taxonomy.json.

A Microsoft check, part of the Zero Trust Assessment pack. Text from ZeroTrustAssessment 3.1.0, © Microsoft, MIT licence.