On 6/29/12 5:45 PM, Willy Santos wrote:
CCI-000025 refers to enforcing information flow control based on
explicit security attributes. This mapping is open to discussion and change.
SRG-OS-000009 CCI-000025 The operating system must enforce information
flow control using explicit security attributes on information, source,
and destination objects as a basis for flow control decisions.
Information flow control regulates where information is allowed to
travel within an information system and between information systems (as
opposed to who is allowed to access the information) and without
explicit regard to subsequent accesses to the information. Examples of
flow control restrictions include: keeping export controlled information
from being transmitted in the clear to the Internet; and blocking
outside traffic claiming to be from within the organization and not
passing any web requests to the Internet that are not from the internal
web proxy. Information flow control policies and enforcement mechanisms
are commonly employed by organizations to control the flow of
information between designated sources and destinations (e.g., networks,
individuals, devices) within information systems and between
interconnected systems. Flow control is based on the characteristics of
the information and/or the information path. Information flow
enforcement mechanisms compare security attributes on all information
(data content and data structure), source and destination objects, and
respond appropriately (e.g., block, quarantine, alert administrator)
when the mechanisms encounter information flows not explicitly allowed
by the information flow policy. Information flow enforcement using
explicit security attributes can be used, for example, to control the
release of certain types of information.
Source and destination are easy -- IPTables. It's when "security
attributes" come into play that I get caught up. Technically we can
enforce this by mandating MCS or MLS enablement. This requirement makes
sense if we were to make a CNSS 12-53 profile, but I'm not convinced
this makes sense for a general purpose security guide.
unmet_impractical_guidance in my opinion