After a period of steady decline that started in 2009, the number of application vulnerabilities has seen a significant increase during the first half of 2012, according to the latest version of Microsoft's Security Intelligence Report (SIR) that was released on Tuesday.
Exploits for security flaws in popular applications like Java and document readers were some of the exploits most commonly detected by Microsoft's security products during the same period.
The new SIR volume 13 contains security analysis and intelligence for 105 countries for the period between January and June 2012, said Tim Rains, a director in Microsoft's Trustworthy Computing group.
According to the report, the number of vulnerabilities found in applications, excluding Web browsers, represent 70 percent of the total number of vulnerabilities disclosed during the first half of 2012.
"Vulnerability disclosures across the industry in 1H12 [first half of 2012] were up 11.3 percent from 2H11, and 4.8 percent from 1H11, mostly because of an increase in application vulnerability disclosures," Microsoft said in its report.
The number of disclosed browser vulnerabilities, which were counted separately, continued its upward trend and even exceeded the number of vulnerabilities reported in operating systems. The number of operating system vulnerabilities disclosed during this period hit its lowest level since 2003, according to the report.
The number of high-severity vulnerabilities increased overall during the first half of 2012 by 9.9 percent, almost reaching their level from the first half of 2011. This was the first increase of the number of high-severity vulnerabilities disclosed during a six-month period since at least 2009.
However, when assessing the threat posed by vulnerabilities, their severity is not the only aspect that counts. A vulnerability's complexity is also an important factor to take into consideration when determining the risk associated with it -- the lower the complexity, the bigger the threat.
"A total of 1,052 low-complexity vulnerabilities -- those that are the easiest to exploit -- were disclosed in 1H12, more than in any period since 1H10," Microsoft said in the report. "However, as a percentage of the total, low-complexity vulnerabilities accounted for 51.6 percent of all disclosures in 1H12, down from 55.3 percent in 2H11."
It's a known fact that attackers prefer to target vulnerabilities that are easy to exploit and which can be exploited with a high degree of reliability.
The statistics show that a lot of vulnerabilities disclosures out there are actually getting easier and easier to exploit, Rains said. "It's really important for software manufacturers to use security mitigations like ASLR, DEP, SEHOP and others so that if there are vulnerabilities in the product, it makes it harder for attackers to exploit them and it drives that access complexity number higher rather than lower."
The attackers' preference for application vulnerabilities was reflected in the exploit detection statistics compiled by Microsoft.
"Blacole, a family of exploits used by the so-called Blackhole exploit kit to deliver malicious software through infected webpages, was the most commonly detected exploit family in the first half of 2012 by a large margin," Microsoft said in the report.
Blackhole contains exploits for vulnerabilities that affect various versions of Adobe Flash Player, Adobe Reader, the Oracle Java Runtime Environment (JRE), Microsoft Data Access Components (MDAC) and other popular software products or components.
An exploit for a Java vulnerability identified as CVE-2012-0507 that was patched by Oracle in February, accounted for the second highest number of exploit detections attributed to the Blackhole kit during the first half of 2012. The highest number of Blackhole exploit detections was for CVE-2010-1885, a vulnerability that affects the Windows Help and Support Center in Windows XP and Windows Server 2003.
Java exploits, excluding those bundled in Blackhole, were the second most common type of exploits detected during the first half of 2012. The number of Java exploit detections increased throughout the period, driven primarily by attacks that targeted the CVE-2012-0507 and CVE-2011-3544 Java vulnerabilities, Microsoft said in the report.
Attackers jumped on the CVE-2012-0507 exploit when it came out and there was a big increase in detection numbers starting in the first quarter of 2012, Rains said. Other than that, attackers seem to be using exploits for older Java vulnerabilities that Oracle has patched a long time ago, back in 2011, 2010 and even as far back as 2008, he said.
The third most commonly detected type of exploit during 1H12 were those that targeted vulnerabilities in document readers and editors, primarily in Adobe Reader and Acrobat.
"People who are keeping all of their software up to date, including Java, have a much better chance of not getting compromised," Rains said.
The data analyzed and presented in SIR was collected by Microsoft from 600 million devices around the world, hundreds of millions of Hotmail accounts, Web pages indexed by the Bing search engine and other sources, Rains said.