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Linux vs Solaris security whitepaper
The level of security achievable in Linux in comparison with Solaris is discussed and the problem of Linux integration into existing enterprise infrastructure is outlined. The author argues that all real and imaginable benefits of Linux notwithstanding adding another OS to the enterprise mix is a decision that should not be taken lightly. Fashion in IT should be resisted and that author agues that it make sense to distinguish from savings and security benefits of moving to EM64T architecture and savings and benefits of moving to Linux.
Typical Linux security problems are compared with Solaris for major dimensions of enterprise security including vulnerabilities and patching framework as well as hardening procedures. The paper contains an executive summary that outlines major conclusions reached. The key finding is that the goal of diminishing (or at least not increasing) of the diversity of operating system environments as a key prerequisite for the secure Linux deployment in the enterprise environment. We judge this goal to be more important for general level of security in the corporation then individual qualities of Linux in security space (or its faults in the same space). if also strongly affects potential savings.
We judge that this central goal requires sacrifices at lease one of existing enterprise OSes and is further complicated by Linux internal fragmentation and existence of two competing enterprise distributions (Red Hat and Suse). The comparative security matrix is presented that provides some insight on Linux security standing among commercial Unixes and Windows 2003 servers. The main conclusion is that currently Solaris leads in security in comparison to Linux, while Windows and Linux has generally similar level of security with Linux having some advantage.
The paper suggests that not only security, but other benefits provided by Linux, should be carefully evaluated against a usage of existing enterprise Unix flavors like Solaris and AIX. The paper stresses the often Linux is surrounded by too much hype and reality of large enterprise deployments looks different from newspaper articles. With Sun opening Solaris and providing version of Solaris for Intel EM64T hardware platform the possibility of using Solaris as an alternative to Linux should be considered in each individual case. In case where Solaris is already used for a particular application (for example e-commerce applications, SAP/R3, etc) just moving the hardware platform from UltraSparc to EM64T architecture looks more promising strategy then adding Linux to the mix.
For most corporate applications securitywise Linux is positioned in between RISK CPU based Unixes (AIX, HP-UX, Solaris) and Windows and is pretty close to Windows in general level of security as well as in the recommended length of patch cycle. Linux has higher number of vulnerabilities per year (close to Windows) then commercial Unixes. As a result Linux servers generally requires more frequent patching (probably monthly like in case of Windows servers) in enterprise environment (many enterprises are able to survive with quarterly patching for all but critical bugs for AIX and Solaris, semiannual for HP-UX).
We also judge that availability of high-quality open source security tools and deep hardening can somewhat offset this patching period disadvantage and might permit using quarterly patching cycle for firewall-protected Linux servers. Linux has better selection of open security tools including better selection of additional PAM modules then Solaris.
All-in-all, in security space large enterprise can get additional benefits from the deployment of Linux, if and only if such a deployment is strategically aligned with the goal of diminishing the operating systems platforms diversity.
Solaris 10 is a pretty revolutionary Os, the first flavor of Unix that deserves to be called XXI century Unix. It is more technically advanced OS then Linux and with the opening of Solaris 10 it should be recommended for enterprise customers, who prefer open systems. Solaris 10 has uniquely instrumented kernel that makes such an amazing tool as DTrace possible. On SPARC hardware Solaris has some unique advantages like self-healing/hardware diagnostic capbilities. Linux is still preferable as a desktop of low cost development workstation due to a wider hardware compatibility and PC friendliness. That might change as Solaris for Opteron matures. Solaris 10 security is dramatically better then security of Linux
Solaris Security and Hardening
Hardening currently is one of the most fashionable topics in security and we will try to cover it more then other topics. It is essentially an attempt to convert a general purpose server into an appliance to improve the level of protection from external as well as internal threats, including the "fifth column" problem; there is no free lunch and hardening generally makes server less Unix user/developers friendly. Given that complexity is the biggest single enemy of security, it's only logical to remove everything that is not essential for the task in hand, users be damned ;-) Although few, if any, fundamentally new Unix vulnerabilities are evident today, most today's Unixes do not include advanced security techniques, let alone the enhancements identified as essential to fight them. Solaris is one of the better Unixes in this respect and it does include some interesting features like advanced file attributes, roles and, especially, zones and privileges management (in Solaris 10+).
The author argues that deep hardening is essentially a process of conversion of general purpose Os into a specialized OS and that's why for organizations without much local talent it might be better to use appliances.
The author formulated two laws of hardening:
Softpanorama First Law of Hardening:
The level of security of any Unix environment can not be significantly different from the level of qualification of system administrator(s) responsible for this environment...
Softpanorama Second Law of Hardening:
If a large discrepancy between the level of qualification of system administrator(s) and the level of hardening of the system exists, the main trend is toward restoring equilibrium at some, not so distant, point...
This article is an attempt of skeptic treatment of this theme and is a modest attempt to fight "security fascism": counterproductive restrictions that complicate user and system administrator lives, while adding nothing of even diminishing security. There is almost no articles on the WEB that are critical or even slightly skeptical about security tools in general and hardening security tools in particular. This article tries to fill the gap.
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Last modified: March 15, 2008