Hackers are aggressively exploiting a just-patched Flash vulnerability, serving attack code "on a fairly large scale" from compromised sites as well as from their own malicious domains, a security researcher said Friday.
The attacks exploit the critical Flash Player bug that Adobe patched June 14 with its second "out-of-band," or emergency, update in nine days.
[ Last week Adobe patched its second Flash zero-day in 9 days and earlier this month hackers exploited a Flash bug in new attacks against Gmail users. | Learn how to greatly reduce the threat of malicious attacks with InfoWorld's Insider Threat Deep Dive PDF special report. ]
"CVE-2011-2110 is being exploited in the wild on a fairly large scale," said Steven Adair, a researcher with the Shadowserver Foundation, a volunteer-run group that tracks vulnerabilities and botnets. "In particular this exploit is showing up as a drive-by in several legitimate websites, including those belonging to various NGOs [non-government organizations], aerospace companies, a Korean news site, an Indian government Web site, and a Taiwanese university."
CVE-2011-2110 is the identifier for the Flash vulnerability assigned by the Common Vulnerabilities and Exposures database.
Attackers are also using the exploit in "spear phishing" attacks aimed at specific individuals, said Adair on the Shadowserver site.
Adair called the attacks "nasty" because the exploit "happens seamlessly in the background," giving victims no clue that their systems have been compromised.
When Adobe patched the vulnerability last week, it conceded that exploits were already in use.
Adair also said there's been an increase in Flash-based attacks. "There has been an ongoing assault against Flash Player for several years now, but especially so in the last three months," Adair said.
Adobe has patched Flash Player four times in the last two months, and six times so far this year. Of the six updates, five addressed zero-day bugs that attackers were already exploiting at the time the patches were issued.
Brad Arkin, Adobe's director of product security and privacy, acknowledged the problems in keeping ahead of attackers, but blamed the popularity of Flash Player for the attention.
"The installed base [of Flash Player] is a real big part of it," said Arkin. "It's such a widely distributed technology that attackers find it worthwhile to invest the time to carry out some kind of malicious activity. They're making an investment for the biggest return possible."
Arkin also argued that attackers get more bang for their buck by rooting out Flash vulnerabilities than they do looking for bugs in individual browsers because virtually every personal computer has the Flash plug-in installed. "Flash is the code [used in the browser] that has the highest market penetration," he said.
According to Adair, the exploit of CVE-2011-2110 has been in use since June 9, five days before Adobe issued its latest security update. Arkin corroborated that timeline.