Improving Web Application Security: Threats and - CGISecurity

416 Part IV: Securing Your Network, Host, and ApplicationAdvantages of a Perimeter NetworkThe perimeter network provides the following advantages:● Hosts are not directly exposed to untrusted networks.● Exposed or published services are the only point of external attack.● Security rules can be enforced for access between networks.Disadvantages of a Perimeter NetworkThe disadvantages of a perimeter network include:● Network complexity● IP address allocation and management● Requirement that the application architecture accommodate the perimeternetwork designSwitch ConsiderationsA switch is responsible for forwarding packets directly to a host or network segment,rather than sharing the data with the entire network. Therefore, traffic is not sharedbetween switched segments. This is a preventive measure against packet sniffingbetween networks. An attacker can circumvent this security by reconfiguringswitching rules using easily accessed administrative interfaces, including knownaccount names and passwords and SNMP packets.The following configuration categories are used to ensure secure switchconfiguration:● Patches and updates● Virtual Local Area Networks (VLANs)● Insecure defaults● Services● EncryptionPatches and UpdatesPatches and updates must be tested and installed as soon as they are available.