InfoSec Musings: Host Protection - Standards and Reference Controls

The Concept of Zero-Trust

To allow for near-future work models, where employees can bring their own mobile devices into the workplace, where “work from home” is standard practice, and where the Data Center is being virtualized and services abstracted to external third party providers, the Security Industry is rethinking the traditional concepts of boundaries and perimeters.

The concept of Zero-Trust is an approach to network and device security that places security at the core of the network and makes it central to all network transactions.

This security centric approach advocates a number of principles to design a secure and flexible network that can protect against modern malware and threats.

Key to this design is the transformation from classical security overlay which simply inspects packets destined to and from the Internet, to ensuring every packet is securely delivered to its destination.

TheZero Trust model provides an innovative data-centric approach to security that protects against sophisticated and targeted attacks.

Regardless of the reason, your data center is expanding beyond your bricks and mortar controls. Many call this the Shrinking Perimeter. (Here, and Here, and Here,) Firewalls at the edge of your network are no longer adequate, and provide for a false sense of comfort.

Empowered users are accessing the network from a variety of devices (e.g., laptops, tablets, and smart phones) and from a variety of locations.

The expectation of anytime anywhere “workspaces” for these users enable new gains in productivity, but also leads to new security challenges in differentiating access based on user, application, device-type or access type (wired, wireless, VPN).

A typical "Data Center" is constantly under threat, both from

external sources as well as internal entities.

What is "Host Protection"?

A “Host Protection” service must ensure the integrity of all resources within the system it is protecting. This would include monitoring of and prevention against unwanted or malicious Network traffic coming in and out of the host, monitoring and management of file integrity, memory integrity, and in the case of Windows Servers, registry integrity.

Host protection will employ centrally managed rules and profiles to ensure that applications on the host behave appropriately and that user and service accounts only have appropriate access to files and applications through whitelisting and blacklisting.

A Host Protection Service must:

•Operate on the significant majority of our Host Operating Systems, and support all of our existing Database and Middleware

•Protect against Zero-Day malware and malicious actor attacks.

•Prevent unauthorized changes or actions, even if the perpetrator has administrative rights.

•Enable demonstrable change control on mission-critical systems.

•Centralize configuration protection across the enterprise, reducing administrative burden.

•Support a library of pre-defined rules that recognize common security events.

•Support policies across logical groups of hosts, helping to ensure the appropriate level of security and ease administrative burden.

•Run pre-defined and customized reports on policies and security events enterprise-wide across heterogeneous systems.

•Automatically trigger alerts and actions, based on pre-defined thresholds, when an event matches a rule.

•Record the event in a centralized corporate SEIM.

What is considered a Host?

In the simplest terms, a “Host” is just a network connected server that provides services to other systems. These services may include database, mail, web, file share, print, etc…

A host can be physical or virtual, and may run any of a dozen operating systems.
A host typically will have additional software added to provide it’s specific functionality. This may include various commercial database and/or application server packages from a multitude of vendors.
A host will generally have a specific purpose or “role” within the data center which would be defined by it’s configuration and/or applications/services running on it.

Similar hosts may be “clustered” together to provide a single service for performance or availability reasons.
Hosts may be grouped together by similar role
Hosts that work together to provide a specific service may be grouped together
Hosts that belong to a specific Business Unit may be grouped together

A managed host may reside anywhere that connectivity and general network security is provided. This includes data center, branch/campus, telco service provider, 3rd party business partner, hosting provider or cloud service provider.

Regardless of Operating System, Almost all Servers are

comprised of the above layers.

All layers above the Operating System kernel are potential places for vulnerabilities, and exploitation. A complete Host Protection Service must take all of these into account.

Protecting a Heterogeneous Environment

Any system or service devised to protect a typical data center environment must be all-encompassing.

Broad Spectrum of Host Operating System coverage:

Any Host protection system deployed must operate and protect the majority of Operating Systems that can be found within the environment. This includes but is not limited to Microsoft Windows Server, IBM AIX , HPUX, Solaris, Linux, VMware, Xen, Microsoft HyperV

Broad Spectrum of Database Server coverage:

Any Host protection system deployed must operate and protect the majority of Database Systems that can be found within the environment. This includes but is not limited to Microsoft SQL Server, Oracle SQL, Sybase, IBM DB2, Ingres, PosGreSQL, MySQL,

•Broad Spectrum of Application Server coverage:

Any Host protection system deployed must operate and protect the majority of Application Servers and Frameworks that can be found within the environment. This includes but is not limited to Microsoft Active Directory, Exchange, SharePoint, and ISA, WebLogic, Oracle, WebSphere, Jboss, IBM Domino, Java, ASP.Net, PHP

Broad Spectrum of Web Server coverage:

Any Host protection system deployed must operate and protect the majority of Web Servers that can be found within the environment. This includes but is not limited to Microsoft IIS, Apache, Tomcat, Weblogic, Oracle

Host Protection - Operating System Layer

File Integrity Monitoring and Prevention:

Identify changes to files in real-time, including who made the change and what changed within the file.

Memory Integrity Monitoring and Prevention:

Identify in real-time, any attempt to modify or corrupt memory outside of the boundaries of that owned or managed by a specific application or service.

Registry Integrity Monitoring and Prevention:

Identify changes to Windows Registry settings in real-time, including who made the change and what changed within the registry.

Device Control:

Identify, prevent and alert on attempts to access system devices which are outside of a particular security profile.

Configuration Monitoring:

Identify policy violations, suspicious administrators or intruder activity in real-time.

Targeted Prevention Policy:

Respond to server incursion or compromise immediately with quickly customizable hardening policies.

Granular Intrusion Prevention Policies:

Protect against zero day threats and restrict the behavior of approved applications even after they are allowed to run with least privilege access controls.

File, system and admin lock down:

Harden virtual and physical servers to maximize system uptime and avoid ongoing support costs for legacy operating systems.

Host Protection - Network Layer

A Host Protection Service must be able to provide a means to identify and control network traffic into and out of the host in question.

Centralized management, reporting, alerting of standard Layer 3 firewall functionality is mandatory

•Source / Destination / Port / Service for each packet must be validated

•Stateful inspection is “nice to have” but not a requirement

Centralized management, reporting, alerting of Layer 4 through 7 “Application Firewall” functionality is mandatory for systems not protected by Network based WAFs. Depending on the purpose of the host, the WAF profile will differ:

•At minimum recognize and protect against OWASP top 10 application vulnerabilities

Intrusion Prevention through any of signature / whitelist / blacklist or heuristics, identify malicious or malformed traffic, and based on policy settings: prevent, log, and alert.

Host Protection - Application Layer

A Host Protection Service must be able to provide a means to identify and control appropriate access within and between applications…..

A host protection service must be able to monitor/collect/report on all resources that an application uses over a period of time to define a “baseline” for appropriate behavior or functionality. These resources include, but are not limited to:

Files

Folders

registry settings

device drivers

Libraries

network connections

service accounts

Once the baseline has been set, any deviation from that must get escalated for review and/or remediation.

This baseline can them be used as a template for other hosts running this same application.

A profile or role can be made, based on this baseline, and a centralized policy defined to manage all hosts that use this template.

Host Protection - Database Layer

A Host Protection Service must be able to proactively prevent or provide remediation for security risks to database systems.

These risks include, but are not limited to:

Unauthorized or unintended activity or misuse by authorized database users, database administrators, or network/systems managers.
Unauthorized or unintended activity or misuse by or by unauthorized users
Unauthorized or unintended privilege escalation
Malware infections causing unauthorized access, leakage or disclosure of personal or proprietary data, deletion of or damage to the data or programs, interruption or denial of authorized access to the database, attacks on other systems
Design flaws and programming bugs in databases and the associated programs and systems, creating various security vulnerabilities

Host Protection - Web Layer

According to OWASP (http://www.owasp.org) and SANS ( http://www.sans.org) The top Web Server vulnerabilities include:

Cross Site Scripting,
SQL Injection,
PHP Injection,
Javascript Injection,
Path Disclosure,
Denial of Service,
Code Execution,

Memory Corruption,
Cross Site Request Forgery,
Information Disclosure,
Arbitrary File,
Local File Include,
Remote File Include,
Overflow,
Other,

OWASP is the emerging standards body for Web application security. In particular they have published the OWASP Top 10 which describes in detail the major threats against web applications. The Web Application Security Consortium (WASC) has created the Web Hacking Incident Database[8] and also produced open source best practice documents on Web application security.

Host Protection - Managing Profiles

A Host Protection Service must be able to centrally manage security profiles and templates, proactively alert on deviations, accept real-time updates from external threat intelligence providers, and feed a centralized SIEM or SOC.

Management of security profiles will allow for granular nesting of roles/profiles

For example:

Nested security profiles, akin to Active Directory’s “Group Policy” management will enable quick access and visibility to host assets by Owner, Role, or Location
A high level role would be assigned to “Operating System Platform”

A nested role would be assigned to SPECIFIC Operating Systems (Windows Server 2003, Windows Server 2007, AIX 5.3, AIX 6.0, HPUX 11…) to refine control

A high level role would be assigned to each Database System Platform

A nested role would be assigned to SPECIFIC Database Systems to refine control
A nested role would be assigned to Critical Database Systems to refine control

A high level role would be assigned to each Application Type

A nested role would be assigned to SPECIFIC Application Instances to refine control

A high level role would be assigned to each Web Server Platform

A nested role would be assigned to SPECIFIC Web Server types to refine control
A nested role would be assigned to Critical Web Servers to refine control

Security profiles can be nested and grouped by role, owner, or location.

To be effective, a Host Protection Service must be managed centrally, receive

live threat and signature updates, and report into a SEIM or SOC in real-time.

So? Who are the players in this field?

Symantec Critical System Protection - To date, Symantec CSP provides the widest coverage for server roles across the most Operating Systems - Both Physical and Virtual. Their System Protection Console cleanly integrates their Security and Malware product suites into a single pane of glass.

TripWire Enterprise File Integrity Monitor - TripWire has been the industry leader in this space for over a decade, and is perfect for small to medium enterprises.
McAfee File Integrity Monitor - McAfee provides a suite of tools that are well integrated for protecting Windows Based Servers and Databases..
IBM Tivoli Virtual Server Protection - VMware ESX protection suite.

SafeNet Data Protection Suite
NewNetTechnologies NNT
Splunk Change Monitor

Cimtrak File Integrity Monitoring

nCircle File Integrity Monitoring