Foxit Reader, a PDF viewer application often used as an alternative to the more popular Adobe Reader, contains a critical vulnerability in its browser plug-in component that can be exploited by attackers to execute arbitrary code on computers.
Details about the vulnerability and how it can be exploited were publicly disclosed last week by Andrea Micalizzi, an independent security researcher from Italy.
No official patch is yet available, according to an advisory from vulnerability intelligence and management company Secunia. The security firm rated the flaw as highly critical because it can be exploited remotely to gain system access.
Foxit's developers have identified the cause of the vulnerability and are working on creating a patch, a Foxit sales and service representative said Friday via email. The patch is expected to be released within one week, she said.
"The vulnerability is caused due to a boundary error in the Foxit Reader plugin for browsers (npFoxitReaderPlugin.dll) when processing a URL and can be exploited to cause a stack-based buffer overflow via e.g. an overly long file name in the URL," Secunia said. "Successful exploitation allows execution of arbitrary code."
The vulnerability has been confirmed in npFoxitReaderPlugin.dll version 220.127.116.110, which is installed by Foxit Reader 18.104.22.1688—the latest version of the program. However, older versions might also be affected, Secunia said.
By default, Foxit Reader installs the plug-in for Mozilla Firefox, Google Chrome, Opera, and Safari Web browsers.
Reputation as secure alternative reader
In the past, Foxit Reader has been suggested by some people in the security community as a more secure and less attacked alternative to Adobe Reader. In fact, Foxit, the company that develops the application, claims on its website that Foxit Reader is "the most secure PDF reader" and is "better than Adobe PDF Reader and Acrobat." According to the company, the program is used by over 130 million users.
"We have confirmed the vulnerability using Firefox, Opera, and Safari," Chaitanya Sharma, advisory team lead at Secunia, said Thursday via email. "At the moment the best mitigation is to disable this add-on in browsers and use other software e.g. Adobe Reader."
The Foxit representative, too, recommended avoiding using the Foxit browser plug-in for Firefox, Chrome, Opera or Safari, but instead suggested using Internet Explorer to view online PDF files.