VMware has released patches for two serious ESXi vulnerabilities that were disclosed during the 2020 Tianfu Cup International PWN Contest.
The Tianfu Cup is the most important hacking contest held in China, the total bonus of the contest this year was up to 1 million US dollars.
The participants successfully tested their exploits against the following software:
- iOS 14 running on an iPhone 11 Pro
- Samsung Galaxy S20
- Windows 10 v2004 (April 2020 edition)
- Adobe PDF Reader
- Docker (Community Edition)
- VMWare EXSi (hypervisor)
- QEMU (emulator & virtualizer)
- TP-Link and ASUS router firmware
The team named “360 Enterprise Security and Government and (ESG) Vulnerability Research Institute,” which is part of the Chinese tech giant Qihoo 360, won the competition. The winning team earned $744,500 of the total $1,210,000 jackpot.
The 360 ESG Vulnerability Research Institute team warned $180,000 for an ESXi guest to host escape exploit.
Experts from VMware who were viewing the hacking contest immediately started working on patches to address the flaws. The company released the first set of patches on Thursday that fixed two vulnerabilities that were exploited by the bug hunters at the hacking competition.
The first vulnerability, tracked as CVE-2020-4004, is a use-after-free vulnerability in XHCI USB controller.
“VMware ESXi, Workstation, and Fusion contain a use-after-free vulnerability in the XHCI USB controller. VMware has evaluated the severity of this issue to be in the Critical severity range with a maximum CVSSv3 base score of 9.3.” reads the advisory.
“A malicious actor with local administrative privileges on a virtual machine may exploit this issue to execute code as the virtual machine’s VMX process running on the host.”
The second flaw, tracked as CVE-2020-4005, is a VMX elevation-of-privilege vulnerability that was caused by the way certain system calls are managed.
“VMware ESXi contains a privilege-escalation vulnerability that exists in the way certain system calls are being managed. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 8.8.” continues the advisory.
“A malicious actor with privileges within the VMX process only, may escalate their privileges on the affected system. Successful exploitation of this issue is only possible when chained with another vulnerability (e.g. CVE-2020-4004).”
The white-hat hackers at the Tianfu contest chained the two vulnerabilities to execute code as the virtual machine’s VMX process running on the host.
The Impacted products are:
- VMware ESXi
- VMware Workstation Pro / Player (Workstation)
- VMware Fusion Pro / Fusion (Fusion)
- VMware Cloud Foundation