Besides Data Leakage Prevention, a Web Application Firewall enhances security by means of guarding from common web-based application threats.
In order to detect application-layer attacks (for example Injection, Cross-Site Scripting, Cross-Site Request Forgery or session/cookie-based flaws in general) and prevent them even before they reach the application itself, the HTTP-traffic (layer 7) gets interpreted and monitored. This allows checking requests (or at least responses) for suspicious activity or known weaknesses that have not been fixed by the maintainer so far on the basis of included signatures or custom rulesets.
This global approach as "Single Point of Detection", combined with a fine-grained control, ensures protection of several systems without the need of touching the existing applications and helps meeting the PCI DSS requirements. The use of cookie-encryption improves the protection against several common threats once more significantly.
Unlike normal firewalls, the Web Application Firewall feature allows eMARA to detect malicious but harmless-looking HTTP-Traffic - an SQL-Injection scenario is only one single example under the plenitude of threats where restricting direct database access is not enough.
Often confused with and mistaken for an Intrusion Detection or -Prevention System, a Web Application Firewall provides security tailored for a web application's needs: In contrast to common IDS/IPS, it comprises inspectable HTTPS, authentication with Single Sign-On, session hijacking etc. protection, request/response manipulation, application-based logging/reporting, and many more HTTP-layer features.