Security Flaws In WinZip Could Allow Attacks

By Larry Seltzer  |  Posted 2004-09-02 Print this article Print

Vendor of popular utility releases service update to address unspecified security vulnerabilities.

WinZip Computing Inc. recently revealed that Version 9.0 of its popular WinZip file compression program is vulnerable to a variety of security attacks. The company has released a "Service Release 1" to address the security problems. The WinZip advisory states that "a number of general internal improvements have been made to the WinZip program to enhance security and reliability." According to the company, the vulnerabilities were found in the course of an internal review and there is no report that any of the problems have been exploited. The alert also said that the service release addresses a specific buffer overflow resulting from certain malformed input on the WinZip command line. This problem was reported by a user, who had no information that it has been exploited, the company said.

A WinZip representative told that earlier versions of the compression utility are also vulnerable to the reported problems and that users should avail themselves of their free upgrade program to move to Service Release 1.

For insights on security coverage around the Web, check out Security Center Editor Larry Seltzers Weblog. In addition, Service Release 1 adds security warnings when the user attempts to execute some potentially dangerous files from within WinZip. However, when testing the new Service Release 1, we received a warning when attempting to execute a .EXE file, but not with an .HTML file. WinZip officials stated that many attacks based on zipped HTML files, such as the recent Bagle attack, will only work on Windows XP due to its Compressed (zipped) Folders feature. It causes all the files in the ZIP archive to appear to be in the same folder, allowing them to execute each other.

This isnt the first vulnerability uncovered in WinZip. Earlier in the year, security researchers uncovered a problem with specially designed MIME archives. Once opened, the attack would trick WinZip into executing code contained in the attacking file. Files handled by WinZip are not normally executable, so many users are less-hesitant to launch them, even when they come from unknown sources. This problem makes those files much more inherently dangerous.

Check out eWEEK.coms Security Center for security news, views and analysis. And for insights on security coverage around the Web, check out Security Center Editor Larry Seltzers Weblog.

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Larry Seltzer has been writing software for and English about computers ever since—,much to his own amazement—,he graduated from the University of Pennsylvania in 1983.

He was one of the authors of NPL and NPL-R, fourth-generation languages for microcomputers by the now-defunct DeskTop Software Corporation. (Larry is sad to find absolutely no hits on any of these +products on Google.) His work at Desktop Software included programming the UCSD p-System, a virtual machine-based operating system with portable binaries that pre-dated Java by more than 10 years.

For several years, he wrote corporate software for Mathematica Policy Research (they're still in business!) and Chase Econometrics (not so lucky) before being forcibly thrown into the consulting market. He bummed around the Philadelphia consulting and contract-programming scenes for a year or two before taking a job at NSTL (National Software Testing Labs) developing product tests and managing contract testing for the computer industry, governments and publication.

In 1991 Larry moved to Massachusetts to become Technical Director of PC Week Labs (now eWeek Labs). He moved within Ziff Davis to New York in 1994 to run testing at Windows Sources. In 1995, he became Technical Director for Internet product testing at PC Magazine and stayed there till 1998.

Since then, he has been writing for numerous other publications, including Fortune Small Business, Windows 2000 Magazine (now Windows and .NET Magazine), ZDNet and Sam Whitmore's Media Survey.

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