Another bug found in Navigator

Netscape confirms the existence of another caching bug in its Web browser, the fourth of its kind in recent weeks.

Paul Festa Staff Writer, CNET News.com
Paul Festa
covers browser development and Web standards.
Paul Festa
2 min read
The bug-battling efforts of Netscape Communications seem to be a case of cache-as-cache-can.

The company today confirmed another caching bug in its Web browser, the fourth in recent weeks.

The latest problem would allow a malicious Web site operator or email sender swipe the contents of a user's browser cache and directory files. Two demonstrations that do just that are posted to the Web; one will read your cache, and the other will read your directory.

The bug is exploited using JavaScript, a scripting language developed by Netscape for interactive Web documents such as pop-up windows and forms. JavaScript is unrelated to the Java programming language, which was developed by Sun Microsystems.

The person who found the bug, Georgi Guninski, notified Netscape of the problem and will reap a $1,000 finder's fee for the discovery, Netscape said today in confirming the security hole.

The bug bears a striking resemblance to two others discovered by bug hunter Dan Brumleve. The first of those, dubbed Cache Cow, reveals cache contents and browsing history. Netscape patched that hole with version 4.07 of the Navigator browser.

The second Brumleve discovery, Son of Cache Cow, affected version 4.07. Netscape fixed that in version 4.5, released last week; but Guninski's bug thwarts the patched upgrade.

Another recently discovered bug prevents Navigator from properly following Web sites' requests that the browser not cache certain pages. In some scenarios involving shared computers, that could lead to breaches of security with user names, passwords, credit card numbers, and other private information.

Netscape and Guninski recommended disabling JavaScript as a workaround for the latest bug. Netscape expects to release a patch or a patched upgrade of Navigator in the next two weeks.