Appliance hardening

The following measures are taken to harden the BMC Discovery appliance when it is built:

• Build the OS using only a small number of packages, all of which are required
• Only the required services are enabled
• Firewall specifically tuned for the appliance
• Unnecessary user accounts are removed
• Disable telnet and ftp (access is through ssh only)
• No remote logins as root
• Set specific kernel parameters such as ICMP echo broadcast
• Set permissions on logging, cron, and configuration to require a privileged user
• Mount options configured to permit only certain operations on specific partitions
• Password quality criteria set
• Remove SETUID privileges from certain applications

The appliance is equipped with its own baseline monitoring system (based on the open source Tripwire product) which can be configured to automatically take action in case of unauthorized changes, such as shutting down the appliance or disabling access.

User management

BMC Discovery application's internal user management service offers all the features required to support ISO 27002 guidelines, specifically:

• Account management
• Password management policies (strength, reuse, lifecycle)
• Granular groups permissions
• Account blocking after authentication failures
• Automatic account lockout (for example, an account not used for 60 consecutive days)
• Automatic session lockout (for example, a session left idle for more than 30 minutes)

Many firms have invested in identity and access management solutions to centralize user management and the permissions to the applications they can access. BMC Discovery can also integrate with a corporate LDAP solution such as Active Directory so that user accounts and group permissions can be managed directly from the LDAP. LDAP groups can be mapped as desired to BMC Discovery groups to simplify overall administration.

Appliance firewall

The appliance firewall is pre-configured to ensure only the following incoming traffic is allowed. Windows proxy communication is always initiated from the appliance so is not listed here.

The open ports listed below are incoming TCP ports to the appliance.

The appliance approach provides a known and understood system in which the interaction between components is designed; the firewall is one of those components. Consequently the appliance is expected to have full control over the firewall. Local Linux system administrators should not make any changes to the appliance firewall as this can compromise the appliance security and any changes will be lost when the it is upgraded.

The only supported change to the appliance firewall is that required to install BMC PATROL. Where such changes are made, the default firewall is used as a fallback.

Where further monitoring or protection is required then it should be placed behind an additional firewall.

Windows proxy hardening

Windows discovery requires a Windows proxy or proxy running on a Windows host to provide the methods (WMI and RemQuery) of accessing Windows systems. The Windows proxy host should be configured to allow the following incoming traffic on the chosen ports.

The ports can be chosen in the proxy manager. The defaults are:

Penetration testing

To ensure BMC Discovery data integrity and confidentiality, the BMC Quality Assurance group performs a thorough assessment on each major and minor release.

UI penetration tests are made with products from WhiteHat Security.

System penetration tests are made with Tenable Nessus. Bastille Linux is used in assessment mode to confirm the security configuration of the system.

Limited/hardened CentOS Linux distribution and security scanners

It is important to note that BMC Discovery does not include a full CentOS Linux build with all of its various packages. In order to improve the security of the product, BMC Discovery only includes those components needed for the operation of the product, rather than those required for a general purpose OS. Omitting unnecessary components decreases risk and increases the overall security of the product.

However, the fact that BMC Discovery doesn't include the full OS can often confuse general purpose security scanners. When the scanner checks the OS, it will report that it is missing patches for components that were never included in the distribution. For example, if BMC Discovery does not include component xyz, it certainly would not include a patch for that component. Since general purpose tools do not first check to see if the component for a patch is present, it simply reports the patch missing without realizing it would make no sense for it to be included on that server.

Known false positives flagged by security scanners

The following security issues have been flagged in the past by some security scanners. In each case they can be shown as not being applicable to BMC Discovery.

• Cyrus SASL Library Base64 Encoder Buffer Overflow — Cyrus IMAP is not part of the BMC Discovery appliance.
• LibPNG could cause denial of service — as there is no UI method of uploading PNG files, the exploit requires command line access as the tideway user.
• LibXML issues could cause crashes — as there is no UI exposure of the XML system, the exploit requires command line access as the tideway user.
• WLAN issue with Kernel — the exploit requires WLAN to be enabled and WLAN kernel extensions to be installed. Neither of these are installed on the appliance.
• OpenSSH X11 Port forwarding hijack — X11 is not installed on the appliance.
• OpenSSL Record of death — not applicable to the version of OpenSSL installed on the appliance.
• Sudo RunAs Group — not applicable to the version of sudo installed on the appliance.
• SQL injection errors — the data store does not use SQL.

The next section describes ways in which you can identify similar false positives.