Top Network Security Risks

Top Network Security Risks

1. Un-patched servers

Server systems used within the corporate network, both ones exposed to the internet, and internal servers that have no direct connection to the internet represent a potential major security risk.

While most IT departments would claim that they are diligent about applying patches as soon as they are available, this risk has to be taken very seriously as even large companies (Microsoft for example) have failed to patch all servers in a timely manner, leading to disruption of internal network traffic by Worms like Code Red and its variants. (Particularly at risk are internal servers that may be neglected because they don’t connect directly to the internet)

2. Un-patched client software

Many common and freely available internet client applications, in particular Internet Explorer, Outlook Express, and Outlook contain security vulnerabilities that may be exploited by a large number of variations on Worm or Viral code. Many of the variations will slip past anti-virus software for several days before anti-virus software makers add their signatures to their software.

Many of these threats can be negated by making sure that all web browsing and e-mail software is regularly updated with all available security patches.

In the particular case of e-mail attachments, the single most dangerous and common security threat today, Using Microsoft Outlook 2000 patched to at least service release 2 and having the extended attachment security option installed completely blocks all executable content in email attachments. Microsoft Office XP includes the dangerous attachment blocking automatically.

It should be noted that no version of Microsoft’s free Outlook Express offers effective blocking of dangerous attachments and users of Outlook Express should therefore have an up to date anti-virus utility installed on their system in addition to training on what attachments are safe to open.

3. Insecure peer to peer file sharing

Individual user’s computers often have file and printer sharing turned on, allowing files to be copied directly between computers within an office. While this is very convenient and often essential to workgroup productivity, care must be taken when deciding what folders to share.

Workstation computer operating systems generally offer much less security than server operating systems. Network aware worms and viruses may take advantage of unprotected shared folders to spread from machine within a LAN. To prevent the possible spread of viruses between computers the root folder, program folders, and operating system folders should never be shared.

Only folders containing data files should be shared, and confidential data that must be shared should be stored on a server where more security is available.

4. Insecure passwords

When possible, any resources shared on a network should be protected by allowing access only with a valid user name and password combination. Passwords should be difficult to guess, and not shared or left in plain sight (i.e. stuck to the monitor.)

A strong password policy allows access to resources to be restricted as needed, to working hours, and an individual’s access to confidential data can be disabled immediately upon termination.