Donald Pipkin's Security Tips for the Week of December 9th
Security Tip for Friday, December 13th, 2002Archive Security Logs Separately from Data Backups
Security logs have a different retention requirement than data. Security logs need to be kept for a long period of time, since intrusions have often been going on for some time before they are discovered. It also eliminates the issues of disclosing data when security information is required for an investigation. Security logs should be handled as evidence even before they become evidence. This means that they must be handled appropriately and the appropriate documentation of their handling must be kept. These procedures and documentation need to show who had access and when to the media and the contained information. Using tamper-proof media, such as WORM or CD-R, adds to the credibility of the process.
Security Tip for Thursday, December 12th, 2002Isolate User Communities with NAT
Network traffic should be isolated wherever it can. Besides increasing the overall performance of the network, it reduces the ability of the information to be intercepted. Using network address translation (NAT) and non-routable networks provides isolation between different user communities. It also keeps users from providing network services (e.g., running a website) to users outside their defined community. Enterprise authentication can provide a better level of accountability than fixed IP addresses, since it identifies the actual user, not the system.
Security Tip for Wednesday, December 11th, 2002Require Business Justification for Access and Privileges
Appropriate security levels are based on business requirements. User access rights and privileges should only be granted to those who have a business need. There are many who may be used to having more privileges than they need and may plead that it makes their jobs easier, but it opens the door to abuse of these privileges. Common users who are given unnecessary privileges and access rights include developers, who do not have a business need to access production data, managers and sponsors, who do not necessarily need access to the projects which they are sponsoring, and any non-administrator who says he needs administrative rights to do his job. Inappropriate assignment of privileges often enables the inside-attacker the access necessary to compromise systems and information.
Security Tip for Tuesday, December 10th, 2002Enforce Least Privileges
All processes should be given the minimum privileges necessary to perform their function for the minimum time required. Least Privileges are often implemented by restricting the permissions on files, devices, and programs, and restricting the number of users who are granted special privileges. File permissions on the system should be minimized, thereby limiting access to the files and programs. Logically placing users into groups based on their access needs can help simplify the permissions settings. Restricting the number of users who are granted privileges minimizes the number of people who can abuse the system. On Unix computers, there is very little reason for anyone who is not performing administrative tasks to have root privileges, even though some people are used to having these privileges.
Security Tip for Monday, December 9th, 2002Perform Risk Analysis for All Projects
Every project has risks, no matter how exciting the increase in revenue or the reduction in costs the project provides. These risks need to be evaluated to provide cost justification. This risk analysis does not have to be a full-blown risk analysis. It can be a quick loss evaluation, which looks at the lost revenue if the project becomes unavailable and the impact to the organization if the information the project accesses is destroyed or disclosed. The destruction of information can cause lost processing which leads to lost revenue. The disclosure of information can affect revenue or future revenue by giving an advantage to the competition. It can cause a loss to the company by damaging the public image of the organization, which can cause a loss of future revenue. The disclosure of customer or personal information could damage someone else and the organization can be liable for this damage. This type of data-oriented loss analysis can be accomplished quickly and will often yield reasonable risk factors.