Windows NT Based Web Security

abdomendebonairSecurity

Nov 2, 2013 (3 years and 5 months ago)

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Windows NT Based

Web Security

COSC 573


By:

Ying Li

Basic Concepts of Windows NT


Advantages


User
-
friendly graphic front end


Point
-
and
-
click configuration


Excellent software development tools


Disadvantages


Relative newcomer to the Internet


A variety of security problems

Basic Concepts of Windows NT


Windows NT Server vs. NT Workstation


Windows NT Server:


More expensive


has complete functionality


can coordinate the activities of other machines,
provide remote access services, run Windows name
resolution, and host the Internet Information Server


Windows NT Workstation


a water
-
down version of the Server product


with most of the server functions disabled


Microsoft Internet Information Server runs only on NT
Server


However, Web servers from other vendors run with the
Workstation version of operating system, as well



From

the

point

of

view

of

system

security,

the

main

difference

between

the

two

flavors

is

that

NT

Workstation

comes

with

an

undesirably

permissive

configuration,

while

NT

Server

is

stricter
.

Basic Concepts of Windows NT (cont’)

Windows NT Security Risks


In

theory,

the

Windows

NT

system

of

access

control

lists,

domains,

and

trust

relationships

provides

a

high

level

of

security
.

In

practice,

many

NT

server

on

the

Internet

are

not

secure
.



How can this be?

Widespread Misconfiguration Problems


An out
-
of
-
the
-
box Windows NT Workstation
installation is not secure.


Most of the system’s files and directories are read/write
by
Everyone,
which means that any local user can
tamper with the system to his heart’s content.


Because of the strange properties of the built
-
in
Everyone

group, there are a variety of ways for
unidentified Internet users to view and /or alter the
system, as well.

Widespread Misconfiguration Problems (Cont’)


Windows NT Server, in contrast, has a more
reasonable set of default permissions when first
installed.


However, it still contains gaps in its configuration
that allow for unwanted mischief.


In practice, many Windows NT Servers are not
installed from scratch but are upgraded from
previous versions of Windows NT or from
Windows 95. In such cases, the access control lists
are probably at their least restrictive setting.

Widespread Misconfiguration Problems (Cont’)


An Additional problem for Windows NT:


Windows NT actually supports two different file
systems: FAT and NTFS. Only NTFS provides
access control lists. Machines that use an FAT file
system have no file protection.

Vulnerability to NetBIOS Attacks


Concept:


Windows NT uses a family of
networking protocols, known collectively as
“NetBIOS,” to provide Windows file sharing,
network printing, and remote system
administration


NetBIOS is network
-
independent. However,
NetBIOS was designed with a local area network
in mind, not large networks like the Internet.


For this reason, it has certain vulnerabilities.

NetBIOS

Vulnerability


Information leakage


NetBIOS will advertise information about a system’s shared
volumes, workgroup name, domain name and machine name
without requiring the remote machine or user to authenticate


Client
-
Controlled fallback to weaker authentication


In order to be compatible with less
-
capable operating systems,
such as Windows for Workgroups, and Windows 95, NetBIOS will
fall back to weaker authentication when a remote client requests it.


Anonymous log
-
in


NetBIOS allows a limited form of anonymous, unauthenticated
log
-
in. Designed to allow machines on the local area network to
exchange information about themselves, this loophole has been
used by would
-
be intruders to gain access to sensitive parts of the
system, such as the registry.

Securing a Windows NT Web Server

1
Apply all service patches

2
Fix the file system permissions

3
Fix the registry access permissions

4
Remove or disable all extraneous network services

5
Add the minimum number of user accounts necessary to
maintain the server

6
Install the server software and adjust file and directory
permissions to restrict unnecessary access

7
Remove or disable unnecessary Web server features, CGI
scripts, and extensions

8
Monitor system and server log files

Apply All Service Packs and Updates


Microsoft releases operating system patches
called “service packs” at regular intervals


These service packs contain patches for
known security holes in the operating
system, as well as other bug fixes and
feature enhancements


Back up your system if it has any valuable
data on it

Fix the File System and Registry Permissions


After applying operating system patches, the next step is
to check and adjust the file system and registry
permissions


To get the benefit of file system permissions, you must
have formatted Windows NT disk partition as NTFS


For fixing the file system, you should log into the
system as
Administrator

and use the
Properties
-
>

Security
-
> Permissions

window to change the access
control lists


For fixing the registry, like the file system, the keys and
values of the Windows registry are protected by access
control lists

An
Example


Directory

C:
\
WINNT
\
PROFILES
\
DEFAULT_USER




C:
\
WINNT
\
PROFILES
\
ALL_USERS


Owner




Administrator

Change contents too


Files and subdirectories

Administrators



Full control

SYSTEM



Full control

Users




Read

Rationale:

These two directories contain common
preferences shared by all users. Users can view the defaults
but not change them

User Rights Policies


The Windows NT User Manager program
establishes certain global user rights. Some
of the rights on a default installation are
inappropriate for Web server machines;
others are simply accident prone. To change
these rights, select Policies
-
> User Rights…
in the User Manager program to bring up
the User Rights Policy

Install Web Server Software


If the software isn’t already preinstalled, go
ahead and install it by running whatever
install program the vendor provides.


The main task at this point is to tune the
directory permissions so that authorized
users can make changes to the Web tree
without having to become full administrator
to do so

Turn off Unnecessary Features



Microsoft IIS and other servers support a few
optional features that potentially can be used by
unscrupulous individuals to gain information
about your system. Unless you really need these
features, you should turn them off.


Directory Browsing


Read
-
Access to the Scripts Directory


Execute
-
Access to Non
-
Scripts Directories


Active Server Pages

Monitor the Web Server and Event Logs


Both the Web server and Windows NT
itself are capable of performing extensive
logging. Although the Web server logs are
turned on by default, NT event logging
(“auditing”) is turned off. It is
recommended to enable it.

Create a Backup System


A recent and complete system
-
wide backup
is essential for recovering from a break
-
in


Even if your system isn’t broken into, a
backup will allow you to recover from
disasters, ranging from hard disk crash to
the accidental deletion of an essential file

?