Security Flaws Haunt PDF, OpenOffice Users

Code execution vulnerabilities are spotted-and patched-in two widely deployed desktop applications.

Serious security vulnerabilities in two desktop applications could allow malicious hackers to plant malicious code on millions of computers, according to warnings from the U.S. governments computer emergency response team.

The more serious of the two is a cross-site scripting bug in Adobes ever-present Acrobat Plug-In, which fails to properly validate user-supplied data.

The issue, which has been patched in Adobe Reader 8 can leverage any Web site that hosts a PDF file to launch code execution or denial-of-service attacks.

According to an advisory from U.S. CERT, a successful attack could be launched via Microsofts Internet Explorer or Firefox browsers.

The issue is trivial to exploit as proof-of-concept code and attack instructions are readily available from multiple sources on the Internet.

In one scenario, an attacker may be able to obtain sensitive data from a user that visits a Web site hosting a legitimate PDF document. Depending on the nature of the Web site, this data may include passwords, credit card numbers and any arbitrary information provided by the user, the U.S. CERT warned.

"Information stored in cookies could be stolen or corrupted," the team warned.

The bug occurs because the Adobe Acrobat Plug-In fails to properly validate URI parameters for scripting code. This allows user-supplied scripts to execute within the context of the Web site hosting the PDF file.

The exploit scenario was originally discussed at the 23rd Chaos Communication Congress during a talk on subverting Web 2.0 applications. Two researchers—Stefano Di Paola and Giorgio Fedon—presented a paper, available here as a PDF file, that explained the associated risks.

Since then, security researchers have chimed in, showing many different ways in which hackers can launch successful attacks against any system running a vulnerable version of Adobe Reader.

WMF code execution bug in OpenOffice

OpenOffice, the free office suite that offers an alternative to the dominant Microsoft Office software, is vulnerable to a WMF (Windows Metafile) code-execution flaw.

The bug, which is rated "highly critical" by security alerts aggregator Secunia, can be exploited by specially rigged WMF file.

"The vulnerability is caused due to integer overflows within the processor for [WMF] files. This can be exploited to cause a heap-based buffer overflow by tricking a user into opening a specially crafted file," Secunia warned.

In a successful attack scenario, a rigged WMF file could cause OpenOffice to execute arbitrary code when the file was opened by the target.

Secunia recommends that OpenOffice users upgrade to Version 2.1, which has been patched.

Red Hat has also shipped updates to correct the issue.

This is the second major flaw to affect OpenOffice, which supports the OpenDocument standard for data interchange. In April 2005, the open-source group was forced to rush out a fix for a buffer overflow that put users at risk of code execution attacks.

Check out eWEEK.coms Security Center for the latest security news, reviews and analysis. And for insights on security coverage around the Web, take a look at Ryan Naraines eWEEK Security Watch blog.