VMSA-2023-0019:VMware Tools updates address a SAML Token Signature Bypass Vulnerability
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 | important | None | None | ||
| VMware Tools | 10.3.x | Linux | CVE-2023-20900 | important | None | None | ||
| [2] VMware Tools (open-vm-tools) | 12.x.x, 11.x.x, 10.3.x | Linux | CVE-2023-20900 | important | [3] 12.3.0 | None | None |
4. References
Fixed Version(s) and Release Notes:
VMware Tools for Windows 12.3.0
Downloads and Documentation:
https://customerconnect.vmware.com/downloads/details?downloadGroup=VMTOOLS1230&productId=1259
https://docs.vmware.com/en/VMware-Tools/12.3/rn/vmware-tools-1230-release-notes/index.html
VMware Tools for Linux 10.3.26
Downloads and Documentation:
https://customerconnect.vmware.com/downloads/details?downloadGroup=VMTOOLS10326&productId=742
https://docs.vmware.com/en/VMware-Tools/10.3/rn/vmware-tools-10326-release-notes/index.html
Mitre CVE Dictionary Links:
https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20900
FIRST CVSSv3 Calculator:
CVE-2023-20900: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
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: [email protected]
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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