Adobe has released an update to address critical flaws in its Flash Player software, one of which is being actively targeted in the wild.
The company said that the Windows and Mac OS X builds of Flash Player 220.127.116.11 and earlier, and Flash Player 18.104.22.1686 and earlier for Linux, must be upgraded to fix a trio of bugs.
Adobe said today's update will "resolve a stack overflow vulnerability that could result in arbitrary code execution (CVE-2014-0498)", fix "a memory leak vulnerability that could be used to defeat memory address layout randomization [ASLR] (CVE-2014-0499), and squash "a double free vulnerability that could result in arbitrary code execution (CVE-2014-0502)."
According to security firm FireEye, the CVE-2014-0502 flaw is exploited by malware to attack folks visiting three nonprofit websites, two of which concern national security and public policy. Researchers believe the infiltration is a targeted operation to gather intelligence.
However, to be vulnerable to this particular attack, a PC must be running Microsoft Windows XP; Windows 7 and Oracle Java 1.6; or Windows 7 and Microsoft Office 2007 or 2010.
"The group behind this campaign appears to have sufficient resources (such as access to zero-day exploits) and a determination to infect visitors to foreign and public policy websites," FireEye said in its alert.
"The threat actors likely sought to infect users to these sites for follow-on data theft, including information related to defense and public policy matters."
According to the security research biz, the CVE-2014-0502 vulnerability "permits an attacker to overwrite the vftable pointer of a Flash object to redirect code execution."
Thus, a miscreant can use a specially crafted Flash file to hijack the plugin, and use return-oriented programming to execute arbitrary code even if security protections ASLR and DEP are enabled. The malicious Flash file downloads a GIF to memory, marks it as executable and runs it. This code then fetches a second program from the internet and executes that too. By this point, the hacker is now running arbitrary software on the machine.
Users can mitigate the threat by upgrading from Windows XP and updating Java and Office. If you have Java 1.6, update Java to the latest 1.7 version. If you are using an out-of-date Microsoft Office 2007 or 2010, update Microsoft Office to the latest version.
These mitigations do not patch the underlying vulnerability. But by breaking the exploit’s ASLR-bypass measures, they do prevent the current in-the-wild exploit from functioning.
To kill off the security bug entirely, Adobe has posted a high-priority fix for its Flash client software. The company is advising all users and administrators to test (if needed) and install the patch as soon as possible to mitigate further exploitation of the flaw.
Users who run Internet Explorer and Chrome will automatically receive the fix through the browser's own update tools. Those on other browsers and platforms can obtain the latest version of Flash through Adobe's download page.
The flaw marks the second out-of-band fix Adobe has had to put out this month. Just over two weeks ago, the company moved to issue a fix for another remote-code-execution vulnerability that had been discovered and targeted in the wild by attackers. ®