VMware has released a new security advisory VMSA-2021-0014: VMware ESXi updates address authentication and denial of service vulnerabilities (CVE-2021-21994, CVE-2021-21995).
Multiple vulnerabilities in VMware ESXi were privately reported to VMware. Updates and workarounds are available to remediate these vulnerabilities in affected VMware products. This advisory documents the remediation of one important issue (CVSSv3 score 7) and one moderate issue (CVSSv3 score 5.3).
The Common Vulnerabilities and Exposures project has assigned the identifiers CVE-2021-21994 to the ESXi SFCB improper authentication vulnerability and CVE-2021-21995 to the ESXi OpenSLP denial-of-service vulnerability.
VMSA-2021-0014 – Description and Workarounds
A malicious actor with network access to port 5989 on ESXi may exploit the SFCB improper authentication vulnerability to bypass SFCB authentication by sending a specially crafted request. SFCB service is disabled by default. The service starts when you install a third-party CIM VIB, for example, when you run the esxcli software vib install -n VIBname command. You can check status and disable SFCB service using:Read More