VMware vCenter Server Improper Input Validation Vulnerability

[ Why it matters ]Priority signals

• Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2021-11-03
• Known to be used in ransomware campaigns
• EPSS: 100% chance of exploitation in the next 30 days (higher than 100% of CVEs)
• Critical severity: CVSS 9.8

[ Description ]Official description

The vSphere Client (HTML5) contains a remote code execution vulnerability due to lack of input validation in the Virtual SAN Health Check plug-in which is enabled by default in vCenter Server. A malicious actor with network access to port 443 may exploit this issue to execute commands with unrestricted privileges on the underlying operating system that hosts vCenter Server.

CISA: VMware vSphere Client contains an improper input validation vulnerability in the Virtual SAN Health Check plug-in, which is enabled by default in vCenter Server, which allows for remote code execution.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 17 Nov 2021): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• packetstormsecurity.com/files/162812/VMware-Security-Advisory-2021-0010.htmlThird Party AdvisoryVDB Entry
• packetstormsecurity.com/files/163487/VMware-vCenter-Server-Virtual-SAN-Health-Check-Rem…ExploitThird Party AdvisoryVDB Entry
• www.vmware.com/security/advisories/VMSA-2021-0010.htmlVendor Advisory
• www.cisa.gov/known-exploited-vulnerabilities-catalogUS Government Resource