<p>VMware issued an advisory about two uninitialized stack memory usage bugs and has released patches and updates for some versions of the affected software.</p>
<h2>Background</h2>
<p>On November 9, VMware published a security advisory to address a Guest-to-Host Escape vulnerability affecting VMware ESXi, Workstation and Fusion. The vulnerability was discovered and released by a security researcher at GeekPwn 2018, an annual security conference in Shanghai, China which took place in late October 2018. The researcher reported the vulnerability to VMware through GeekPwn.</p>
<p><script type="text/javascript" id="vidyard_embed_code_LSmcyWYaoeLA58zsiMv2JA" src="//play.vidyard.com/LSmcyWYaoeLA58zsiMv2JA.js?v=3.1.1&type=inline"></script></p>
<p><i>Source: <a href="https://twitter.com/ChaitinTech/status/1057526019127676929">@ChaitinTech on Twitter</a>.</i></p>
<h2>Vulnerability details</h2>
<p>According to <a href="https://www.vmware.com/security/advisories/VMSA-2018-0027.html">VMware’s Security Advisory</a>, Zhangyanyu of <a href="https://www.chaitin.cn/en/">Chaitin Tech</a> reported two uninitialized stack memory usage bugs (CVE-2018-6981 and CVE-2018-6982) in the vmxnet3 virtual network adapter used in VMware. VMware notes that the vulnerability does not affect non-vmxnet3 virtual network adapters.</p>
<p>Exploitation of CVE-2018-6981 can lead to a guest-to-host escape, allowing the guest to execute code on the host, while exploitation of CVE-2018-6982 can lead to information disclosure from host to guest. In a tweet that includes <a href="https://twitter.com/ChaitinTech/status/1057526019127676929">a video demonstration of the exploit</a>, Chaitin Tech asserts that this is the first time that anyone has escaped VMware EXSi and obtained a root shell on the host.</p>
<h2>Urgently required actions</h2>
<p>VMware’s Security Advisory includes patch availability details for consumers and businesses. Tenable’s Security Response team strongly encourages patching VMware ESXi versions and upgrading VMware Workstation and VMware Fusion using the table below:</p>
<p><img src="/sites/drupal.dmz.tenablesecurity.com/files/images/blog/vmware_patch_vers_0.PNG" width="753" height="798" alt="" /></p>
<p>Source: <a href="https://www.vmware.com/security/advisories/VMSA-2018-0027.html">VMware Security Advisory </a></p>
<h2>Identifying affected systems</h2>
<p>A list of Tenable plugins to identify this vulnerability will appear <a href="https://www.tenable.com/plugins/search?q=cves%3A(%22CVE-2018-6981%22%20OR%20%22CVE-2018-6982%22)&sort=&page=1">here</a> as they’re released.</p>
<h2>Get more information</h2>
<ul>
<li><a href="https://www.vmware.com/security/advisories/VMSA-2018-0027.html">VMware Security Advisories: VMSA-2018-0027</a></li>
<li><a href="https://twitter.com/ChaitinTech/status/1057526019127676929">Video Demo of Guest-to-Host Escape by Chaitin Tech</a></li>
</ul>
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