For the second time in nine days, Adobe on Tuesday patched a critical vulnerability in Flash Player that hackers were already exploiting.
Adobe also updated its popular Reader PDF viewer to quash 13 new bugs and several older ones the company had not gotten around to fixing.
[ 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. ]
The memory corruption vulnerability in Flash Player was pegged "critical" by Adobe, which said that the bug could "potentially allow an attacker to take control of the affected system" in an accompanying advisory. "There are reports that this vulnerability is being exploited in the wild in targeted attacks via malicious Web pages," the advisory added.
Adobe last issued an emergency update -- dubbed "out-of-band" -- on June 5, when it fixed a critical flaw that attackers were exploiting to steal Gmail login credentials.
Those attacks were different from the ones Google disclosed the week before, when it accused Chinese hackers of targeting specific individuals , including senior U.S. and South Korean government officials, anti-Chinese government activists and journalists, with messages that tried to trick them into entering their username and password on a fake Gmail login screen.
Google, which bundles Flash Player with Chrome, also updated its browser Tuesday to include the just-patched version of Flash.
Adobe has patched Flash Player four times in the last two months, and six times so far this year.
Although most Flash vulnerabilities can also be exploited using specially crafted PDF documents -- Adobe's Reader includes "authplay.dll," a custom version of Flash that renders content within PDFs -- Adobe said the newest Flash bug doesn't impact Reader.
All but two of the 13 new bugs were pegged "critical" by Adobe, which like Apple doesn't rate flaws with a multi-label scoring system. Instead, it uses the phrase "could lead to remote code execution" to note that hackers may be able to hijack the system and plant malware on the machine by exploiting the bug.
The baker's dozen of new bugs included memory corruption vulnerabilities, buffer and heap overflow bugs, a cross-document scripting flaw, a DLL load hijacking vulnerability and one simply labeled a "security bypass" bug.
That last was a Reader X-only vulnerability that under certain circumstances lets an attacker force the Reader browser plug-in to download a non-PDF file, Adobe said in a reply to follow-up questions.