Red Hat ENTERPRISE LINUX 5 - VIRTUAL SERVER ADMINISTRATION, Руководство по развертыванию

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Chapter 42. Security Overview
596
Exploit Description Notes
eavesdropping on the connection
between the two nodes. Remote attacker must have access
to a compromised system on a LAN
in order to perform such an attack;
usually the cracker has used an active
attack (such as IP spoofing or man-in-
the-middle) to compromise a system
on the LAN.
Preventative measures include
services with cryptographic key
exchange, one-time passwords, or
encrypted authentication to prevent
password snooping; strong encryption
during transmission is also advised.
Service
Vulnerabilities An attacker finds a flaw or loophole
in a service run over the Internet;
through this vulnerability, the attacker
compromises the entire system and
any data that it may hold, and could
possibly compromise other systems on
the network. HTTP-based services such as CGI
are vulnerable to remote command
execution and even interactive shell
access. Even if the HTTP service
runs as a non-privileged user such
as "nobody", information such as
configuration files and network maps
can be read, or the attacker can
start a denial of service attack which
drains system resources or renders it
unavailable to other users.
Services sometimes can have
vulnerabilities that go unnoticed
during development and testing;
these vulnerabilities (such as
buffer
overflows
, where attackers crash a
service using arbitary values that fill
the memory buffer of an application,
giving the attacker an interactive
command prompt from which they may
execute arbitrary commands) can give
complete administrative control to an
attacker.
Administrators should make sure that
services do not run as the root user,
and should stay vigilant of patches and
errata updates for applications from
vendors or security organizations such
as CERT and CVE.
Application
Vulnerabilities Attackers find faults in desktop and
workstation applications (such as e-
mail clients) and execute arbitrary
code, implant trojan horses for future
compromise, or crash systems.
Further exploitation can occur if
the compromised workstation has Workstations and desktops are more
prone to exploitation as workers do
not have the expertise or experience
to prevent or detect a compromise; it
is imperative to inform individuals of
the risks they are taking when they