Web Tier Bypasses App Tier
Security review finds the web servers can talk directly to the database — they shouldn't be able to
Scenario
The customer-facing application is built in three tiers, each on its own subnet: a web tier that talks to the public Internet, an application tier that the web tier talks to for business logic, and a database tier that only the application tier is supposed to reach. A routine security review found that web-tier servers can connect directly to the database tier, completely bypassing the application tier — a serious defense-in-depth violation, since a compromised web server should never be able to touch the database directly.
Learning objectives
- acl
- nftables
- least privilege
Topology and configuration
This environment contains 4 devices (3 Hosts, 1 Router). You configure and troubleshoot the networking skills listed above.