VMware this week announced patches for a critical remote code execution vulnerability in VMware Cloud Foundation and NSX Data Center for vSphere (NSX-V).
Tracked as CVE-2021-39144 (CVSS score of 9.8), the security defect exists in XStream, an open source library to serialize objects to XML and back.
The bug impacts all XStream iterations until and including version 1.4.17. Only out-of-the-box versions are affected, but not those where XStream’s security framework was set up with a whitelist limited to the minimal required types.
“Due to an unauthenticated endpoint that leverages XStream for input serialization in VMware Cloud Foundation (NSX-V), a malicious actor can get remote code execution in the context of ‘root’ on the appliance,” VMware notes in its advisory.
NSX-V 6.4.x reached end of general support in January 2022. VMware says that it typically does not mention end-of-life (EOL) products in its advisories, but in this case it has decided to release the patch due to the vulnerability’s critical severity.
VMware says that all NSX-V versions prior to 6.4.14 and VMware Cloud Foundation (VCF) 3.x releases are impacted. The vulnerability has been addressed with the release of NSX-v 6.4.14 and VCF 18.104.22.168.
VMware’s advisory also describes a medium-severity XML External Entity (XXE) vulnerability in VCF (CVE-2022-31678) that could be exploited by unauthenticated attackers to cause a denial-of-service (DoS) condition or to leak information.
According to Tenable senior staff research engineer Satnam Narang, the critical severity of the vulnerability and the fact that VMware chose to release a patch for it may indicate that it is easy to exploit and that in-the-wild exploitation may be observed soon.
“While this vulnerability isn’t on the level of the Log4j flaws, it serves as a reminder of the supply chain risks through the use of open-source software,” Narang said.