VMware on Thursday announced releasing patches for a couple of serious ESXi vulnerabilities that were demonstrated at a recent hacking contest in China.
At the 2020 Tianfu Cup International PWN Contest, which took place earlier this month in China, participants earned a total of more than $1.2 million for exploits targeting Chrome, Safari, Firefox, Adobe Reader, Docker, VMware ESXi, CentOS, the iPhone, the Samsung Galaxy S20 phone, Windows, and routers from TP-Link and Asus.
The 360 ESG Vulnerability Research Institute from Chinese cybersecurity company Qihoo 360 earned more than $740,000 of the total, including $180,000 for a VMware ESXi guest to host escape exploit.
VMware was monitoring the event and it immediately started working on patches. The virtualization giant announced the first patches on Thursday, less than two weeks after Tianfu Cup ended.
An advisory published by VMware describes two vulnerabilities that were chained at the hacking competition — it’s unclear if there are other flaws involved as well.
One of the security holes, CVE-2020-4005, is a privilege escalation issue caused by the way certain system calls are managed. This high-severity flaw allows an attacker who has privileges within the VMX process only to elevate permissions on the targeted system.
This vulnerability can be chained with CVE-2020-4004, an issue rated critical that the Qihoo 360 researchers exploited to execute code as the virtual machine’s VMX process running on the host. The flaw is a use-after-free affecting the XHCI USB controller and exploitation requires local admin privileges on the VM.
CVE-2020-4004 affects ESXi, Fusion, Workstation and VMware Cloud Foundation. Patches and updates have been released, except for Cloud Foundation, for which fixes are pending.
In the case of CVE-2020-4005, it impacts ESXi and Cloud Foundation. Fixes are available for ESXi and they are pending for Cloud Foundation.
Google and Mozilla have also patched the Chrome and Firefox vulnerabilities disclosed at the competition.
At last year’s Tianfu Cup, researchers from Qihoo 360 earned $200,000 for a VMware ESXi exploit. The vulnerabilities leveraged for that exploit were also patched by the virtualization giant after roughly two weeks.
VMware this week also patched a series of vulnerabilities in its SD-WAN Orchestrator product that could have allowed an unauthenticated attacker to remotely execute arbitrary code, which researchers say could lead to the shutdown of an enterprise network or traffic steering.
Related: Patch for Critical VMware ESXi Vulnerability Incomplete
Related: VMware Patches Critical Code Execution Vulnerability in ESXi
Related: Google Researcher Finds Vulnerability in VMware Virtualization Products

Eduard Kovacs (@EduardKovacs) is a contributing editor at SecurityWeek. He worked as a high school IT teacher for two years before starting a career in journalism as Softpedia’s security news reporter. Eduard holds a bachelor’s degree in industrial informatics and a master’s degree in computer techniques applied in electrical engineering.
More from Eduard Kovacs
- Intel Boasts Attack Surface Reduction With New 13th Gen Core vPro Platform
- Dole Says Employee Information Compromised in Ransomware Attack
- High-Severity Vulnerabilities Found in WellinTech Industrial Data Historian
- CISA Expands Cybersecurity Committee, Updates Baseline Security Goals
- Exploitation of 55 Zero-Day Vulnerabilities Came to Light in 2022: Mandiant
- Organizations Notified of Remotely Exploitable Vulnerabilities in Aveva HMI, SCADA Products
- Waterfall Security, TXOne Networks Launch New OT Security Appliances
- Hitachi Energy Blames Data Breach on Zero-Day as Ransomware Gang Threatens Firm
Latest News
- CISA, NSA Issue Guidance for IAM Administrators
- Analysis: SEC Cybersecurity Proposals and Biden’s National Cybersecurity Strategy
- Intel Boasts Attack Surface Reduction With New 13th Gen Core vPro Platform
- Cisco Patches High-Severity Vulnerabilities in IOS Software
- ‘Nexus’ Android Trojan Targets 450 Financial Applications
- Tackling the Challenge of Actionable Intelligence Through Context
- Dole Says Employee Information Compromised in Ransomware Attack
- Backslash Snags $8M Seed Financing for AppSec Tech
