Important

VMSA-2023-0019.1
7.1
2023-08-31
2023-09-05
CVE-2023-20900
VMware Tools updates address a SAML Token Signature Bypass Vulnerability (CVE-2023-20900)
1. Impacted Products
  • VMware Tools
2. Introduction

A SAML token signature bypass vulnerability in VMware Tools was responsibly reported to VMware. Updates are available to remediate this vulnerability in the affected VMware products.

3. SAML Token Signature Bypass vulnerability (CVE-2023-20900)

Description

VMware Tools contains a SAML token signature bypass vulnerability. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 7.1.

Known Attack Vectors

A malicious actor that has been granted Guest Operation Privileges in a target virtual machine may be able to elevate their privileges if that target virtual machine has been assigned a more privileged Guest Alias.

Resolution

To remediate CVE-2023-20900 apply the patches listed in the 'Fixed Version' column of the 'Response Matrix' found below.

Workarounds

None.

Additional Documentation

None.

Notes

[1] VMware Tools 10.3.26 only applies to the older Linux releases.
[2] A version of open-vm-tools that addresses CVE-2023-20900 will be distributed by Linux vendors. 
[3] Fixed versions may differ based on the Linux distribution version and the distribution vendor.

Acknowledgements

 VMware would like to thank Peter Stöckli of GitHub Security Lab for reporting this issue to us.

Response Matrix

Product Version Running On CVE Identifier CVSSv3 Severity Fixed Version Workarounds Additional Documentation
VMware Tools
12.x.x, 11.x.x, 10.3.x
Windows
CVE-2023-20900
7.1
important
None
None
VMware Tools
10.3.x
Linux
CVE-2023-20900
7.1
important
None
None
[2] VMware Tools (open-vm-tools)
12.x.x, 11.x.x, 10.3.x
Linux
CVE-2023-20900
7.1
important
[3] 12.3.0
None
None
4. References
5. Change Log

2023-08-31 VMSA-2023-0019
Initial security advisory.

2023-09-05 VMSA-2023-0019.1
Updated VMSA to clarify the known attack vectors.

 

6. Contact

E-mail: security@vmware.com

PGP key at:
https://kb.vmware.com/kb/1055 

VMware Security Advisories
https://www.vmware.com/security/advisories 

VMware Security Response Policy
https://www.vmware.com/support/policies/security_response.html 

VMware Lifecycle Support Phases
https://www.vmware.com/support/policies/lifecycle.html 

VMware Security & Compliance Blog  
https://blogs.vmware.com/security 

Twitter
https://twitter.com/VMwareSRC

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