Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Vulnerabilities / Threats

End of Bibblio RCM includes -->
06:05 PM
Connect Directly

Thousands of VMware vCenter Servers Remain Open to Attack Over the Internet

Three weeks after company disclosed two critical vulnerabilities in the workload management utility, many organizations have not patched the technology yet, security vendor says.

Thousands of instances of VMware vCenter Servers with two recently disclosed vulnerabilities in them remain publicly accessible on the Internet three weeks after the company urged organizations to immediately patch the flaws, citing their severity.

The flaws, CVE-2021-21985 and CVE-2021-21986, basically give attackers a way to take complete control of systems running vCenter Server, a utility for centrally managing VMware vSphere virtual server environments. The vulnerabilities exist in vCenter Server versions 6.5, 6.7, and 7.0.

Related Content:

CISA Warns Criminals Seek to Exploit Critical VMware Bug

Special Report: Assessing Cybersecurity Risk in Today's Enterprises

New From The Edge: How President Biden Can Better Defend the US From Russian Hacks

VMware released patches addressing the vulnerabilities on May 25. At the time, the company urged organizations with affected versions of the software to apply the patches quickly because of the high level of risk the flaws presented to enterprise security. "The decision on how to proceed is up to you," the company had noted in an advisory at the time. "However, given the severity, we strongly recommend that you act."

Yet three weeks after that announcement — and a subsequent warning of exploit activity from the Department of Homeland Security's Cybersecurity and Infrastructure Security Agency (CISA) — many vulnerable vCenter Server instances remain unpatched and open to attack, according to Trustwave. The company recently conducted a search on Shodan to see how many vulnerable instances of the utility it could find that were still accessible over the Internet.

The search turned up a total of 5,271 instances of VMware vCenter Servers publicly exposed to the Internet. Of that, 4,019 were confirmed as being vulnerable to the two threats that VMware identified last month. Another 942 hosts were running old and end-of-life versions of vCenter server, Trustwave said in a report this week.

Karl Sigler, senior security research manager at Trustwave SpiderLabs, says these instances are likely affected by the two flaws as well and unpatched because no patches are currently available for those systems.

"The vulnerabilities are critical and can result in complete system takeover via remote code exploitation," Sigler says. The flaws are also relatively easy to exploit for any attacker with even a rudimentary understanding of HTTP and so-called REST application programming interfaces . "An attacker wouldn't even need specialized tools or software, as an entire attack can be performed with standard tools like 'curl,'" Sigler says.

VMware's vCenter Server is designed to give organizations a way to centrally manage vSphere environments across hybrid cloud platforms. According to the company, one of the remote code execution vulnerabilities exists in a virtual storage area network (vSAN) plug-in that ships along with vCenter Server. The flaw provides any attacker who can reach vCenter Server over the Internet a way to gain access to it, regardless of whether the organization uses vSAN or not. The second issue involves a mechanism that was introduced to strengthen plug-in authentication.

Mitigation Measures
In releasing patches for the two issues, VMware also described mitigation measures for organizations that couldn't immediately apply them for any reason. The company identified organizations upgrading to vSphere 7 as being among those that would likely have to make a choice between patching or workaround because of how the patches would affect the upgrade. The company also made it a point to note that applying the patches would only impact the ability to manage workloads and not workload availability itself. "This is an important point to convey to change managers, too, as they may not understand that the workloads will continue running," VMware said in its advisory last month.

Sigler says the complexity and difficulty associated with patching in these environments is likely one reason why so many affected vCenter Servers remain unpatched. "For production systems used by multiple teams, you need to coordinate with those teams for expected downtime," he notes. "Many times, patches need to be tested in lab environments prior to being pushed to production systems to verify that the patch won't cause more issues than they solve."

Trustwave has so far not observed any evidence of the vulnerabilities being exploited in the wild. But given the number of exposed systems and ease of exploitation, there's likely to be a lot of exploit activity soon, Sigler warns. "Administrators should be patching as soon as they possibly can."

Jai Vijayan is a seasoned technology reporter with over 20 years of experience in IT trade journalism. He was most recently a Senior Editor at Computerworld, where he covered information security and data privacy issues for the publication. Over the course of his 20-year ... View Full Bio

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
I Smell a RAT! New Cybersecurity Threats for the Crypto Industry
David Trepp, Partner, IT Assurance with accounting and advisory firm BPM LLP,  7/9/2021
Attacks on Kaseya Servers Led to Ransomware in Less Than 2 Hours
Robert Lemos, Contributing Writer,  7/7/2021
It's in the Game (but It Shouldn't Be)
Tal Memran, Cybersecurity Expert, CYE,  7/9/2021
Register for Dark Reading Newsletters
White Papers
Current Issue
The Promise and Reality of Cloud Security
Cloud security has been part of the cybersecurity conversation for years but has been on the sidelines for most enterprises. The shift to remote work during the COVID-19 pandemic and digital transformation projects have moved cloud infrastructure front-and-center as enterprises address the associated security risks. This report - a compilation of cutting-edge Black Hat research, in-depth Omdia analysis, and comprehensive Dark Reading reporting - explores how cloud security is rapidly evolving.
Flash Poll
How Enterprises are Developing Secure Applications
How Enterprises are Developing Secure Applications
Recent breaches of third-party apps are driving many organizations to think harder about the security of their off-the-shelf software as they continue to move left in secure software development practices.
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
PUBLISHED: 2023-01-28
Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and 3.1.0.beta2 on the `beta` and `tests-passed` branches, when submitting a membership request, there is no character limit for the reason provided with the request. This could potentially allow a user to...
PUBLISHED: 2023-01-28
OpenMage LTS is an e-commerce platform. Versions prior to 19.4.22 and 20.0.19 contain an infinite loop in malicious code filter in certain conditions. Versions 19.4.22 and 20.0.19 have a fix for this issue. There are no known workarounds.
PUBLISHED: 2023-01-28
Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and 3.1.0.beta2 on the `beta` and `tests-passed` branches, the contents of latest/top routes for restricted tags can be accessed by unauthorized users. This issue is patched in version 3.0.1 on the `stable...
PUBLISHED: 2023-01-28
Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, a malicious user can cause a regular expression denial of service using a carefully crafted user agent. This issue is patched in version 3...
PUBLISHED: 2023-01-28
Discourse is an open-source discussion platform. Prior to version 3.0.1 on the `stable` branch and version 3.1.0.beta2 on the `beta` and `tests-passed` branches, someone can use the `exclude_tag param` to filter out topics and deduce which ones were using a specific hidden tag. This affects any Disc...