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Linux Attacks On the Rise, Says Report - But It's Not As Simple As That

Linux is now the most hacked server operating system in government, says report - and the Linux community responds

A report in Government Computer News (GCN) draws attention to two security flaws reported in some Linux kernels that could let local users execute arbitrary code on systems running the affected versions of Linux:
  • A vulnerability in the ncp_lookup of the Linux 2.6 kernel could let a local user get elevated privileges on the system.
  • A flaw in the memory remapping system call in versions of the 2.2, 2.4 and 2.6 kernels could give a user root access.

Fixes have been released for both new Linux vulnerabilities. (Information on the vulnerabilities and on the fixed versions is available online at www.securitytracker.com.)

Here's how the GCN report continues:

The vulnerabilities, reported by Security Tracker, have come about the same time as a study that found Linux to be the most hacked server operating system in government.

The study, by British security consulting firm mi2g Ltd., said attacks on Linux outpaced those on Microsoft Windows for the first time in January. The study focused only on direct digital attacks carried out by hackers, rather than on exploits by worms and viruses, which have primarily targeted Windows systems.

Linux accounted for 57 percent of successful attacks on government systems studied, followed by Windows at 35 percent. This is in sharp contrast to August, when Windows accounted for 51 percent of successful attacks and Linux just 14 percent. For the first time, the study found no successful attacks against government servers running the Berkley Software Distribution family of open-source systems, or the Mac OS X, based on the Darwin open-source kernel.

“The swift adoption of Linux last year within the online government community, coupled with inadequate training and knowledge on how to keep that environment secure, has contributed” to the shift, said D.K. Matai, mi2g executive chairman.

The mi2g study has come under immediate criticism from the Linux community around the world. One dissenting online opinion takes issue with some of the claims at the mi2g site, saying:

mi2g has not been in the security industry since 1995. The continued claims of collecting data that far back are unsubstantiated and unverified. DK Matai's insistence of working on a PhD in information security appear to be nothing more than wishful thinking. These are cornerstones of mi2g's claims of being experts in the field, and appear to be lies.

A more general observation, from someone posting to Slashdot the moment news of the report broke, was that the mi2g methodology "is not the best way to conduct research" - a reference to the fact that group discounted the recent wave of worms, viruses and other attacks that have affected Windows systems worldwide, and confined the study to overt digital attacks by hackers. Here is the post:

"When I was doing research at NIH we would say of this sort of thing: 'After discarding all data to the contrary, the hypothesis was proven.'

While this research may show that Linux servers are over-represented in overt acts of hacking, this does not statistically make the Linux OS the least secure. Attacking a particular system simply makes it popular for attack. In order to characterize Linux, or any other OS, as the least secure, there would need to be evidence that an equal amount of other OS's were unsuccessfully attacked or the success rate was lower. Other variables that would required controls would be the hacker, level of sophistication of attack, etc. etc.

To say that '...while Linux servers were the most vulnerable...' only means that they may have been the most targeted. I am not saying that the conclusions of this research are incorrect, I am saying that from what I have read, they cannot come to those conclusions."

Another excellent post came from Slashdot reader J M Dority, who wrote as follows:

"No OS is secure. The only defense OSS has is that patches can be released quickly, while Microsoft took 200 days to fix ASN.1 (for which a similar problem was found and fixed very quickly in the BSDs and Linux last March).

How many large companies/organizations running Windows where hacked last year? The point is, most companies/organizations don't report IT security breaches, certainly not like GNU did. If you have a high-profile company, and someone with enough skill wants to, you WILL be hacked eventually, regardless of your choice of OS. Most blackhats don't have the skill level that the GNU attack took, and even that probably could have been prevented, but there is a tradeoff between high security and convenience, and a 0day exploit is hard to stop, unless you can stay awake 24/7 and process incoming ethernet frames in your head fast enough to determine their intent before forwarding them.

I personally would rather be attacked once a month and know of the attack instantly than be attacked once a year and not know. Security starts at the power outlet, once you plug a machine in, you're vulnerable."

More Stories By Linux News Desk

SYS-CON's Linux News Desk gathers stories, analysis, and information from around the Linux world and synthesizes them into an easy to digest format for IT/IS managers and other business decision-makers.

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Most Recent Comments
Delfin Ramirez 02/27/04 08:38:22 PM EST

The problem is not itself the system we use ( Win, Unix, etc.)
People use computers and , as we know, computers are blind.
System's administrators must have vision.

Fecal Extrusion 02/24/04 09:55:20 AM EST

It has been long known that Microsoft succssfully
Brainwashed the UK govt. That's why they so openly embrace
Windows with loving arms.

I wouldn't be surprised if Microsoft funded that study.
Any time I hear/read stuff like that I can just smell the
stench of Microsoft nearby.

Datore 02/24/04 03:40:52 AM EST

Let's compare to robbery and banks.
If we use the same type of investigation, we will discover
that banks is one of the most attacked for robbery. So of
course banks are less secure than the grocery down the
corner, because they are almost never robbed.
And what about hospitals ? Since so many people die there
it must be a very dagenrous place ??

John Lynch 02/22/04 03:03:22 PM EST

I think this is an administration problem. Within the company I work, they have migrated to Linux and we don't have enough technical staff that really understands Linux. On many occasions patches have not been applied on time.

David Mohrin 02/22/04 02:17:13 PM EST

To editors of Linuxworld: Your posting FUD without checking sources AGAIN.

If you had even bothered to google news the source of the press release, MI2G
http://news.google.com/news?num=100&hl=en&scoring=d&q=MI2G
http://www.google.com/search?q=MI2G
You would have either discovered the slashdot story
http://slashdot.org/article.pl?sid=04/02/21/142239
Or other pages serously questioning the reliability of MI2G
http://www.attrition.org/errata/charlatan/mi2g-history.html
http://www.theregister.co.uk/content/55/28233.html
http://www.nwfusion.com/news/2002/1107msfoul.html

Even if you refuse to trust the above, just to put some balance in the posted article...

The MI2G study of servers "did not include other methods of intrusion such as viruses and worms

"The same firm mi2g also wrote the following

http://www.mi2g.com/cgi/mi2g/press/190204.php

QUOTE
London, UK - 19 February 2004, 13:30 GMT - mi2g Intelligence Unit datashows that partially as a result of the growth of the MyDoom family ofmalware, lingering effects of Mimail, Dumaru, Sobig, Swen, Klez, Sober,Yaha, BugBear and Fizzer, and also as a result of new strains of Bagle,February 2004 has already become the worst month for malware proliferation on record with 10 days to go. As of today, the total economic damage from all malware epidemics in February is estimated to lie between $43.8bn and $53.6bn worldwide, two thirds more than the record breaking previous month of January.
UNQUOTE

Symantic also predicted the following in its September 2003 Internet Threat report.

http://downloads.securityfocus.com/library/InternetThreatReportSept2003.pdf
QUOTE
Blended Threats
BLENDED THREATS INCREASING IN SPEED AND FREQUENCY
Blended threats, which use combinations of malicious code to begin, transmit, and spread attacks, are increasing and are among the most important trends to watch and guard against this year. By using multiple techniques, blended threats can spread to large numbers of hosts, causing rapid and widespread damage. During the first half of 2003, blended threats increased nearly 20% over the last half of 2002. One blended threat alone, Slammer, disrupted systems worldwide in less than a few hours. Slammer s speed of propagation, combined with poor configuration management on many corporate sites, enabled it to spread rapidly across the Internet and cause outages for many corporations. Companies hit by Slammer were not harmed as badly as they might have been, because it was designed to propagate quickly, degrade networks, and to compromise vulnerable systems rather than cause destruction or steal confidential data. Corporations that had updated firewalls, updated patches, and virus protection throughout the enterprise were prepared for this attack.

Blended-Threat Targets
MICROSOFT IIS VULNERABILITIES
Microsoft IIS is one of the most widely deployed Web servers throughout the world. Symantec has documented several high-severity vulnerabilities affecting it. Their characteristics render these vulnerabilities attractive targets for future blended threats. Given Microsoft IIS s susceptibility to past blended threats such as Code Red and Nimda, Symantec believes that it may again be hit by highly destructive malicious-code attacks.

MICROSOFT INTERNET EXPLORER VULNERABILITIES
Several vulnerabilities allow attackers to compromise client systems through Web pages containing embedded malicious code. Others can enable the easy and almost undetectable installation of spyware, which allows attackers to extract confidential data.

THEFT OF CONFIDENTIAL DATA
The release of Bugbear and its variant Bugbear.B (discovered in early June 2003) were good examples of theft of confidential data. Once systems were infected, confidential data was extracted such as file names, processes, usernames, keystrokes, and other critical system information, and delivered to a third party, potentially compromising passwords and decryption keys. Furthermore, it appears that the creator of Bugbear specifically targeted banks. During the first half of 2003, Symantec saw a 50% increase in confidential data attacks using backdoors. By granting access to compromised systems, backdoors allow data to be exported to unauthorized individuals. For example, entire sessions can be logged, and passwords for systems and applications can be taken. Companies need to implement controls that make it difficult for malicious code to steal confidential data, such as updated firewalls, patch management policies, intrusion detection, virus protection, and so on.

ATTACKERS EXECUTING COMMANDS FROM THOUSANDS OF INFECTED SYSTEMS
Once a system is compromised, an attacker can install malicious code known as a bot that allows the attacker to use the system for future scanning or as a launching point for future attacks (such as planned, distributed denial-of-service attacks). Once a system has become infected, the attacker can maintain a running list of the entire botnet (network of infected systems) by simply issuing commands through Internet Relay Channel (IRC is a common communication channel used by bots). Afterwards, all listening bots (sometimes numbering in the thousands) will execute any command issued by the attacker. Symantec examined an automated tool like this, which accounted for supposable Nimda (blended threat) traffic, after it was captured in a Honeypot network3.

CONCLUSION
The evidence in this report clearly shows that the risk of blended threats and attacks is rising. Understanding how to budget for security and what products and services are needed will involve some of the most important decisions that every corporation faces in the 21st century. The trends that we discuss in this report help executives understand some of the threats faced by their systems administrators every day. Symantec carefully monitors other potential threats such as the rise in peer-to-peer attacks (including instant messaging), mass mailers (like SoBig), the general trend toward theft of confidential information, and the rapid increase in the number of Windows 32 (Win32) threats.
UNQUOTE