SECURING FIBRE CHANNEL FABRICS - Brocade

The Brocade SAN Security ModelThe model resembles an onion with layers of skin around its core (OK,perhaps a “mutant” onion with three cores). At the center, the threebasic types of SAN hardware are represented by the three smaller circlesfor the HBA, storage hardware (disk and tape), and fabricinfrastructure hardware (switches, directors, and routers). Surroundingthe SAN hardware is a series of concentric circles outlining the layersof security to protect that specific type of hardware.Protecting the HBAThe HBA is the link between the hosts running applications and theSAN, in which the application data is stored. The HBA requires specificprotection measures since it has its unique set of vulnerabilities. Tohelp mitigate the risks associated with these vulnerabilities, each HBAvendor offers specific security features and enhancements.HBA security features can include the following:• LUN masking, generally implemented at the storage device (diskarray) level, however, some HBA vendors provide the ability to performLUN masking at the HBA level.• DH-CHAP support, as defined in the ANSI T11 FC-SP standard, toauthenticate an HBA when joining a fabric. This is usually done toprotect against WWN spoofing attacks.• Secure management interfaces and protocols such as SSH tosecure the CLI interface and SSL to secure the GUI interface.How real is WWN spoofing? This question certainly comes up frequentlyand the answer is not always simple. It is possible to changethe WWN on any HBA; tools are available from most HBA vendors thatallow users to do this and some are also available as freeware.For example, an attacker from the outside could theoretically compromisea server in a DMZ (although originally a military term, in computersecurity, Data Management Zone), reconfigure the compromisedserver's WWN to the WWN of a production server’s WWN, and capturedata intended for the other host.How likely is this to occur? With proper security measures in place, thistype of attack is very unlikely. However, if the value of an asset is particularlyhigh or attractive to someone, then the likelihood of an attackon that asset increases, no matter how difficult or sophisticated theattack needs to be. Generally though, only the most sensitive environments,such as military and intelligence organizations, as well as someprivate organizations, require protection against WWN spoofingattacks.Securing Fibre Channel Fabrics 93