IDX·October 30, 2026·1 min read
A web application firewall (WAF) sits between visitors and your website and inspects each request. Requests that match known attack patterns are blocked before your application ever sees them.
What a WAF is good at
- Common injection attacks, such as SQL injection and cross-site scripting attempts.
- Known vulnerability exploits, often with rules released soon after a popular plugin's flaw is published.
- Brute-force login attempts and abusive bots.
- Rate limiting, slowing down clients that send too many requests.
What it cannot do
- Fix outdated software. A WAF may block a known exploit, but attackers vary their requests. Updating the plugin removes the flaw itself.
- Protect against stolen passwords. A legitimate login with a stolen password looks normal.
- Stop large network-level DDoS attacks on its own; that needs protection at the network edge. See DDoS protection basics.
- Replace backups. If something does get through, you need a clean copy to restore.
Tuning matters
A WAF set too strictly blocks real customers, for example a form submission containing code snippets. Too loose, and it lets attacks through. Start with well-maintained rule sets, monitor what gets blocked, and add exceptions carefully.
Where WAFs run
- On the server, as a module of the web server.
- At a CDN or proxy in front of your site.
- Built into security plugins for platforms such as WordPress.
A layered approach
The strongest setups combine a WAF with regular updates, strong authentication, least-privilege access, monitoring and tested backups.
At IDX
Our NOC and SOC team designs and monitors protection for business infrastructure, from WAF rules to incident response. Contact us to review your setup.
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