Hi everyone, I’ve been working on setting up AWS WAF for my team’s new marketing automation platform. We handle a lot of landing pages and customer data, so security is suddenly a huge priority for me, even though it’s a bit outside my usual comfort zone with email campaigns and A/B testing.
I was pretty overwhelmed by all the rule groups and configurations, so I tried to build a Terraform module that sets up a sensible baseline. It includes some common managed rules (like the AWSManagedRulesCommonRuleSet) and basic rate limiting for our login and form submission endpoints. The idea is to have a starting point that we can then tweak based on analytics and what we see in the logs.
I’m really nervous about rolling this out, though. I’d be so grateful if some of you with more experience could take a look and tell me if I’m on the right track or missing something obvious. Specifically:
- Are there any critical security rules for web applications that I’ve overlooked?
- How do you handle tuning these rules without blocking legitimate traffic from our landing pages?
- Does this setup play nicely with tools like Google Analytics or our CRM integrations, or could it interfere?
I’ve shared the module in our company’s repo, but I can summarize the main parts if that’s helpful. Just don’t want to make a costly mistake for my team.
🙏 jane
Hey, this is a super common spot to be in. I felt the same way when I first had to set up WAF on our GCP load balancer. The number of knobs is insane.
For the tuning part, we started with everything in count mode only for a week. That way you can see what would have been blocked without actually blocking anything. It was a huge relief for the marketing team worried about losing leads.
Does your module have a simple switch for that? Like a variable to set the default action for all rules to count?
Still learning
Nervous is the right feeling. The "set it and forget it" mentality with managed rule sets is a great way to create a false sense of security.
>critical security rules for web applications that I've overlooked?
You've got the basics, but remember, the AWSManagedRulesCommonRuleSet is a generic baseline. It's not going to catch much that's specific to your marketing platform. Think about the data flows: is that rule set sophisticated enough to spot weird patterns in your form submissions, or would it just block a weirdly formatted but legitimate lead gen payload? Probably the latter.
On tuning without blocking real traffic, sure, start in count mode. But the real trap is thinking a week's logs are enough. Your traffic patterns next month during a campaign will look nothing like this week's. You'll tune based on a quiet period, then launch a big promo and wonder why your conversion rate tanked. 😬
As for GA and CRM integrations, those are classic sources of "false positive" behavior that look like bot traffic. If your rate limiting is too aggressive on form endpoints, you'll absolutely nuke submissions from legitimate tools. Have you actually mapped which IPs those services might originate from?
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Your worry about Google Analytics and CRM integrations is valid, but you're focusing on the wrong layer. A WAF shouldn't touch those outgoing calls unless your own app is misconfigured to proxy them. The real interference will be with your form handlers and any client-side scripts that get caught by XSS rules.
You're putting a generic filter in front of a specialized app. The managed rules will absolutely block legitimate lead gen payloads. A sales rep pasting a weirdly formatted address from their spreadsheet into your form? That's a block. The count-mode advice is fine, but it's a temporary salve. The actual fix is writing custom rules that understand your data patterns, which is the exact work you were trying to avoid.
Just my 2 cents