VMware Patches Vulnerabilities in ESXi, ThinApp
VMware on Tuesday announced the availability of patches for vulnerabilities impacting its ESXi hypervisor, Cloud Foundation hybrid cloud platform, and ThinApp application virtualization tool.
The most severe of these issues is CVE-2021-21994, an improper authentication flaw in SFCB (Small Footprint CIM Broker) as used in ESXi. With a CVSS score of 7.0, the bug is deemed important.
According to VMware, a malicious actor that has network access to port 5989 on ESXi may send a specially crafted request to bypass SFCB authentication. The vulnerability is only exploitable if the SFCB service is running. By default, however, the service is not enabled.
In its advisory, the cloud computing and virtualization technology company also details CVE-2021-21995, a heap out-of-bounds read issue in ESXi OpenSLP that could lead to denial of service (DoS). With a CVSS score of 5.3, the vulnerability is considered moderate severity.
The bug, VMware says, could be exploited by a malicious actor that has network access to port 427 on ESXi to cause a DoS condition.
The company has published a series of workaround recommendations for both vulnerabilities and also released patches, and advises customers to install them as soon as possible.
Tracked as CVE-2021-22000 and having a CVSS score of 6.8, the security hole in VMware ThinApp is caused by insecure loading of DLLs.
The DLL hijacking bug could be exploited by a malicious actor with non-administrative privileges to elevate privileges to administrator level on the Windows operating system on which ThinApp is installed.
No workarounds exist to remediate the vulnerability, but VMware has released a patch and recommends applying it to remain protected. VMware ThinApp version 5.2.10 fixes the bug.