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VMware Calls Attention to High-Severity vCenter Server Flaw

Cloud computing and virtualization technology giant VMware on Tuesday shipped an urgent security patch for a flaw in its vCenter Server product and warned users to expect public exploit code within minutes of disclosure.

“Time is of the essence,” VMware said in a note calling attention to CVE-2021-22005, a file upload bug in the vCenter Server Analytics service. “The ramifications of this vulnerability are serious and it is a matter of time – likely minutes after the disclosure – before working exploits are publicly available.”

The company has attached a CVSSv3 base score of 9.8 to underscore the severity of the vulnerability.

The Palo Alto, Calif. company said a malicious actor with network access to port 443 on vCenter Server may exploit this issue to execute code on vCenter Server by uploading a specially crafted file.

VMware took the extra step of warning that this type of security flaw is perfect for ransomware actors. “With the threat of ransomware looming nowadays the safest stance is to assume that an attacker may already have control of a desktop and a user account through the use of techniques like phishing or spear-phishing, and act accordingly. This means the attacker may already be able to reach vCenter Server from inside a corporate firewall, and time is of the essence.

[ READ: US Gov Warning: VPN, Network Perimeter Product Flaws Under Constant Attack ]

In total, the VMware patch bundle documents at least 19 security vulnerabilities affecting the VMware vCenter Server and VMware Cloud Foundation products.  These flaws range in severity and could expose users to privilege escalation and information disclosure attacks.

The company urged customers to prioritize the privilege escalation issues because of their value to ransomware gangs launching data encryption and extortion attacks.

“In this era of ransomware it is safest to assume that an attacker is already inside your network somewhere, on a desktop and perhaps even in control of a user account, which is why we strongly recommend declaring an emergency change and patching as soon as possible,” VMware said in a notice accompanying the patch. 

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Ryan Naraine is Editor-at-Large at SecurityWeek and host of the popular Security Conversations podcast series. Ryan is a veteran cybersecurity strategist who has built security engagement programs at major global brands, including Intel Corp., Bishop Fox and GReAT. He is a co-founder of Threatpost and the global SAS conference series. Ryan's past career as a security journalist included bylines at major technology publications including Ziff Davis eWEEK, CBS Interactive's ZDNet, PCMag and PC World. Ryan is a director of the Security Tinkerers non-profit, an advisor to early-stage entrepreneurs, and a regular speaker at security conferences around the world. Follow Ryan on Twitter @ryanaraine.