1. Mecanismo
no proyectado para comunicaciones, que es usado para transferir información violando
la seguridad (ITSEC).
2. Canal de
transmisión que permite a un proceso transmitir datos violando la política de
seguridad del sistema (TCSEC).
Puede
presentarse como canal de almacenamiento (storage channel) o como canal de
tiempo (timing channel). El primero sucede cuando un proceso puede escribir,
directa o indirectamente, en un almacenamiento que puede leer, directa o
indirectamente otro proceso distinto utilizando este procedimiento para pasarse
ilícitamente información. Típicamente requiere un recurso (por ejemplo, un
disco) compartido por dos sujetos con diferentes habilitaciones de seguridad.
En el
segundo, un proceso difunde información a otro modulando su propio uso de los
recursos del sistema (por ejemplo, tiempo de UCP) lo que afecta al tiempo de
respuesta. Ello puede ser observado e interpretado por el segundo proceso.
[Ribagorda:1997]
Transmisión
de información de manera oculta sobre un canal que transmite información. Se
aplica especialmente a algunos esquemas de firma digital. [CESID:1997]
An unauthorized
communication path that manipulates a communications medium in an unexpected,
unconventional or unforeseen way in order to transmit information without
detection by anyone other than the entities operating the covert channel. [CNSSI_4009:2010]
Determination of the extent
to which the security policy model and subsequent lower-level program
descriptions may allow unauthorized access to information. [CNSSI_4009:2010]
Covert channel involving the
direct or indirect writing to a storage location by one process and the direct
or indirect reading of the storage location by another process. Covert storage
channels typically involve a finite resource (e.g., sectors on a disk) that is
shared by two subjects at different security levels. [CNSSI_4009:2010]
Covert channel in which one
process signals information to another process by modulating its own use of
system resources (e.g., central processing unit time) in such a way that this
manipulation affects the real response time observed by the second process. [CNSSI_4009:2010]
1. (I) An unintended or unauthorized
intra-system channel that enables two cooperating entities to transfer
information in a way that violates the system's security policy but does not
exceed the entities' access authorizations.
(See: covert storage
channel, covert timing channel, out-of-band, tunnel.)
2. (O) "A
communications channel that allows two cooperating processes to transfer
information in a manner that violates the system's security policy."
[NCS04]
[RFC4949:2007]
(I) A system feature that
enables one system entity to signal information to another entity by directly
or indirectly writing a storage location that is later directly or indirectly
read by the second entity. (See: covert channel.) [RFC4949:2007]
(I) A system feature that
enables one system entity to signal information to another by modulating its
own use of a system resource in such a way as to affect system response time
observed by the second entity. (See: covert channel.) [RFC4949:2007]
an enforced, illicit
signalling channel that allows a user to surreptitiously contravene the
multi-level separation policy and unobservability requirements of the TOE (this
is a special case of monitoring attacks).
TOE - Target of Evaluation
[CC:2006]
the use of a mechanism not
intended for communication to transfer information in a way that violates
security. [ITSEC:1991]
A communication channel that
allows a process to transfer information in a manner that violates the system's
security policy. [TCSEC:1985]
A covert channel that
involves the direct or indirect writing of a storage location by one process
and the direct or indirect reading of the storage location by another process.
Covert storage channels typically involve a finite resource (e.g., sectors on a
disk) that is shared by two subjects at different security levels. [TCSEC:1985]
A covert channel in which
one process signals information to another by modulating its own use of system
resources (e.g., CPU time) in such a way that this manipulation affects the
real response time observed by the second process. [TCSEC:1985]