VMware bug lets attackers zap 'real'
Windows
No
patch yet for shared folders flaw
February 24, 2008 (Computerworld) A critical vulnerability in VMware Inc.'s virtualization software for Windows lets attackers escape the "guest" operating system and modify or add files to the underlying "host" OS, the company has acknowledged.
As of Sunday, there was no patch available for the flaw, which affects VMware's Windows client virtualization programs, including Workstation, Player and ACE. The company's virtual machine software for Windows servers, and for Mac- and
Linux-based hosts, are not at risk.
The bug was reported by Core Security Technologies, makers of the penetration testing framework CORE IMPACT, said VMware in a security alert issued last Friday. "Exploitation of this vulnerability allows attackers to break out of an isolated Guest system to compromise the underlying Host system that controls it," claimed Core Security.
According to VMware, the bug is in the shared folder feature of its Windows client-based virtualization software. Shared folders lets users access certain files -- typically documents and other application-generated files -- from the host OS and any virtual machine on that physical system.
"On Windows hosts, if you have configured a VMware host-to-guest shared folder, it is possible for a program running in the guest to gain access to the host's complete file system and create or modify executable files in sensitive locations," confirmed VMware.
VMware has not posted a fix, but instead told users to disable shared folders.
The Palo Alto, Calif.-based company also made it clear that the vulnerability isn't present in its server line of virtual machine software: VMware Server and ESX Server do not use shared folders. Newer version of VMware's Windows client virtualization tools also disable shared folders by default, the company added; users must manually turn on the feature to be vulnerable.
A similar bug was reported by VeriSign Inc.'s iDefense Labs to VMware in March 2007, and patched by the latter about a month later.
Friday's alert, however, was the second security-related notice posted by VMware in two days. Thursday, VMware patched its ESX Server line to quash five bugs that could be used to slip past security restrictions, launch denial-of-service attacks, or compromise virtualized systems.
The increased reliance on virtual machines, particularly on enterprise servers, has come with its own set of security problems, researchers and IT administrators have noted previously. Sunday, an analyst with the Internet Storm Center (ISC) extended that warning to desktop virtualization users, particularly security professionals.
"We make an extensive use of virtualization technologies for multiple purposes: malware analysis, incident response, forensics, security testing, training, etc., and we typically use the client versions of the products," said Raul Siles in a post to the ISC blog. "It is time to disable the shared folder capabilities."
注意了！VMware的致命BUG可導致「真正的」Windows被幹掉
喜歡用虛擬機來玩病毒的朋友注意了！VMware公司已經確認，該公司推出的虛擬機軟體存在著一個漏洞，可以使攻擊者脫離「客戶」操作系統，並在「主機」中修改和添加文件。截至到目前位置，尚無修正可以堵住這個漏洞！所有Windows版本，包括Workstation、Player、ACE都受此漏洞影響。而Windows servers、Mac、Linux版本暫時沒有發現這個問題。這個漏洞是有Core Security Technologies公司發現，VMWare表示「攻擊者可以利用此漏洞衝破客戶系統，從而控制主機」。
說明了！ 沒有絕對安全的系統
