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When Patches Aren't Applied

By Ryan Naraine

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Enterprise IT administrators, bombarded by daily software vulnerability warnings on a daily basis, have not been serious about applying security patches despite the clear danger of worms, viruses and intruder attacks.

That's the word from online security experts who estimate that up to 50 percent of all enterprises could be sitting ducks for hacker attacks because of unpatched, vulnerable computer systems.

While it is impossible to figure exact percentages of critical or important patches that have been downloaded and installed, experts believe the application of fixes are delayed for months, even with the increased awareness after the recent Code Red and Slammer incidents.

Last year alone, network administrators had to deal with more than 80 percent more vulnerabilities than in 2001, according to a report from Symantec (Quote, Company Info), which provides anti-virus software. Microsoft (Quote, Company Info), the world's leading software vendor, issued 72 security alerts in 2002 and 10 already this year.

A Microsoft spokesman told internetnews.com there are no exact percentages available for issued patches and downloaded because there is not a 1:1 ratio of patch downloads to patch applications.

"While technologies such as Windows Update, Auto Update and SUS have increased patch uptake, we cannot provide detailed download statistics. Large enterprises often download a patch to a local server, then deploy it across thousands of computers, therefore; patch downloads are not indicative of the numbers of computers protected," the spokesman explained.

Marty Lindner, team leader for incident handling at the CERT Coordination Center, agreed it was nearly impossible to figure out actual percentages. In large enterprises, for instance, Lindner said the term 'patch download' doesn't apply because those systems are typically protected through an outsourced software maintenance contract.

"In a major organization, if they have 100,000 machines, they aren't downloading and installing 100,000 patches. It really is hard to measure because, even for smaller business, you have no way of knowing what happens once a patch is downloaded. You don't know how many machines it is applied to and who is sharing a patch with who," Lindner explained.

Lindner's CERT/CC, the federally funded clearinghouse for warnings from all major vendors, reported 4,129 vulnerabilities in 2002, almost double the number issued the previous year. The Center's statistics show an alarming trend upwards but Lindner said the lack of information is still a major setback in the Center's quest to secure susceptible systems.

Sheer Volume
Lindner blamed the administrators' indifference to patch applications on the large amounts of security information being shuttled to enterprises on a daily basis. "The sheer volume of security information that's seen by a network administrator is mind-boggling. In many cases, it's a huge task just figuring out which patch applies to you," he explained.

Even after the sysadmin is made aware of the problem, it's not a straightforward care of applying a patch, Lindner explained. "People believe you solve the problem by applying a patch but, typically, you can do a configurating change or turn off the offending software and secure your system," he added.

"The first challenge is to decide which patches apply to your system. After you have weeded through that, then you have to apply the patch and test it outside of production. When you apply the patch, you have to make the blind assumption that it's fixing whatever needs to be fixed. Even then, you take the risk that you will break something that used to work," Lindner said in an interview, arguing that faulty patches have been just as destructive as the vulnerable software it was meant to fix.

Thomas Kristensen, chief technology officer as security research firm Secunia, believes network admins are more likely to patch holes in mail servers and Web servers in a timely manner.

"Generally, in a medium-sized business, they'll use Windows update and get patches relevant to their systems and, even then, they'll apply the patches based on whether it is important or not," Kristensen said.

He said bug warnings around Web browsers or other client systems are routinely ignored because they are deemed unimportant. "Sometimes, they will hesitate and delay fixing a faulty browser for several months and assume they aren't vulnerable because they're using a firewall but that is a dangerous assumption. The intruders are sophisticated and are using attack scenarios that penetrate the firewall," Kristensen told internetnews.com.

In many small- and medium-sized enterprises, Kristensen said it boiled down to a matter of available resources to deal with patch applications. "They just don't have the tools or software to distribute patches in the network. They'll have to do it individually and it is a tremendous task for a one-man staff to be running from machine to machine to plug a hole," he said.

CERT/CC's Lindner agreed that the urgency to apply fixes was determined by the cost factor. "Many corporations choose to measure the risk associated with the cost of patching a system. Sometimes, it is a conscious decision that patching computer systems is not a high enough priority to spend big dollars to do it," Lindner asserted.

So what to do when all of those patches are critical? Read more on Page 2."It is quite possible, companies have chosen, for better or worse, to use their money on marketing as opposed to patching systems. It is, in many cases, a straightforward decision," Lindner said, warning that it's dangerous to downplay the serious risk that can be caused by an exposed system.

David Litchfield, co-founder of Next Generation Security Software (NGSS), estimated that less than 5 percent of vulnerable systems are patched in a timely manner. "Within a few weeks of the advisory going out, about 20 percent are fixed but I'd say about 50 percent of enterprises don't even bother to apply the patches," he said in an interview from his U.K. office.

"A large part of the problem is that the administrator is not even aware of the patch. It is surprising that in some enterprises, there are no vulnerability assessment (VA) tools being used," he argued.

At other times, Litchfield said IT admins are simply "fed up" with the large amount of patches being issued and are content to wait for service packs that provides a bulk fix. That's why the Code Red and Slammer attacks were so successful. There were literally millions of unpatched systems around the world," he added.

Litchfield called on governments around the world to take the lead in educating companies and consumers about the serious risks involved with bad software. "It would be a good start a massive user awareness campaign but the problem is coaching people to read those documents. It's like taking the horse to the water but you can't make them drink."

Secunia's Kristensen agreed that user awareness was a huge problem, even with the increased publicity from the mainstream media. "One of the big reasons why people aren't installing patches is the lack of knowledge about them actually existing," he declared.

During internal research, Kristensen said admins are more eager to patch a hole in a Web server or a mail server but, even then, only about 50 percent of the holes in susceptible servers are plugged.

"Even with all the media attention, I don't think there's much more than two-thirds of services out there that's been updated," he added.

Crying Wolf?
Then, there is the cry-wolf syndrome, born out of too many 'critical' warnings being issued, particularly by Microsoft. The Redmond, Wash.-firm acknowledged there were legitimate fears that too many high-level alerts were being issued.

Steve Lipner, director of security assurance for Microsoft, recently announced the Severity Rating Criteria would be modified to specify clearly which bugs needed to be addressed immediately.

"There is also a widespread feeling that the Severity Ratings are difficult to understand and apply. For these reasons, we have modified (the criteria) to help customers more easily evaluate the impact of security issues," Lipner explained.

Of Microsoft's 72 warnings in 2002, more than half were tagged with the 'critical' rating. Of the ten issued this year, five have been described as critical. The 'critical' rating is reserved only for "a vulnerability whose exploitation could allow the propagation of an Internet worm without user action," Microsoft explained.

The new ratings criteria carry an 'important' tag for flaws that could result in compromise of the confidentiality, integrity, or availability of users' data, or of the integrity or availability of processing resources. Below that, the company issues 'moderate' or 'low' warnings.

For CERT/CC's Lindner, the issue goes beyond software vulnerabilities and points to faults with the engineering process. "The root cause of problematic patches and problematic software is bad software engineering practices. That's where we have to fix things," Lindner declared.

"When we find flaws in software and we have to build a patch, we're using the same bad software engineering practices to build the patch to fix the software that's poorly engineered. It's a vicious circle," he added.

Even as the experts continue to decry the slow pace of patch applications, Lindner suggested a two-fold approach to fixing things. First, he called for widespread adoption of better software enginnering practices and, more importantly, widespread adoption of developing foolproof architecting protocols.

He said too many built-in flaws were being discovered in some of the most crucial protocols. "Even if you wrote air-free software, there would still be vulnerabilities because the protocols themselves have problems. That's what he have to concentrate on fixing," said Lindner.