One of the biggest things happened this week was the highly-organized hacking attack on Google, Adobe, and among other 33 big firms. And IE seems to be playing a big rule in these attacks.
It was first claimed by both Google and Adobe that they were hacked using malicious PDF files that exploited a zero-day vulnerability in Adobe’s popular Reader. But It seems like that IE should be the one accused.
Microsoft has issued a Security Advisory (979352) on Jan 14, 2010 that states
Our investigation so far has shown that Internet Explorer 5.01 Service Pack 4 on Microsoft Windows 2000 Service Pack 4 is not affected, and that Internet Explorer 6 Service Pack 1 on Microsoft Windows 2000 Service Pack 4, and Internet Explorer 6, Internet Explorer 7 and Internet Explorer 8 on supported editions of Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2 are affected.
The vulnerability exists as an invalid pointer reference within Internet Explorer. It is possible under certain conditions for the invalid pointer to be accessed after an object is deleted. In a specially-crafted attack, in attempting to access a freed object, Internet Explorer can be caused to allow remote code execution.
It also states that this active attack so far are attempting to against IE 6, and they haven’t seen attacks against other versions of IE mentioned above.
There is no release yet so far to fix this vulnerability but this advisory provides 5 factors that help to mitigate the thread.
- Protected Mode in Internet Explorer on Windows Vista and later Windows operating systems limits the impact of the vulnerability.
- In a Web-based attack scenario, an attacker could host a Web site that contains a Web page that is used to exploit this vulnerability. However, an attacker would have no way to force users to visit these Web sites. Instead, an attacker would have to convince users to visit the Web site, typically by getting them to click a link in an e-mail message or Instant Messenger message that takes users to the attacker’s Web site.
- An attacker who successfully exploited this vulnerability could gain the same user rights as the local user. Users whose accounts are configured to have fewer user rights on the system could be less affected than users who operate with administrative user rights.
- By default, Internet Explorer on Windows Server 2003 and Windows Server 2008 runs in a restricted mode that is known as Enhanced Security Configuration. This mode sets the security level for the Internet zone to High. This is a mitigating factor for Web sites that you have not added to the Internet Explorer Trusted sites zone.
- By default, all supported versions of Microsoft Outlook, Microsoft Outlook Express, and Windows Mail open HTML e-mail messages in the Restricted sites zone. The Restricted sites zone helps mitigate attacks that could try to exploit this vulnerability by preventing Active Scripting and ActiveX controls from being used when reading HTML e-mail messages. However, if a user clicks a link in an e-mail message, the user could still be vulnerable to exploitation of this vulnerability through the Web-based attack scenario.
So, the basic principles still help.