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CVE-2023-28436 Detail


Tailscale is software for using Wireguard and multi-factor authentication (MFA). A vulnerability identified in the implementation of Tailscale SSH starting in version 1.34.0 and prior to prior to 1.38.2 in FreeBSD allows commands to be run with a higher privilege group ID than that specified in Tailscale SSH access rules. A difference in the behavior of the FreeBSD `setgroups` system call from POSIX meant that the Tailscale client running on a FreeBSD-based operating system did not appropriately restrict groups on the host when using Tailscale SSH. When accessing a FreeBSD host over Tailscale SSH, the egid of the tailscaled process was used instead of that of the user specified in Tailscale SSH access rules. Tailscale SSH commands may have been run with a higher privilege group ID than that specified in Tailscale SSH access rules if they met all of the following criteria: the destination node was a FreeBSD device with Tailscale SSH enabled; Tailscale SSH access rules permitted access for non-root users; and a non-interactive SSH session was used. Affected users should upgrade to version 1.38.2 to remediate the issue.


CVSS 3.x Severity and Metrics:

Base Score:  8.0 HIGH
Vector:  CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  5.7 MEDIUM
Vector:  CVSS:3.1/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

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Hyperlink Resource
https://github.com/tailscale/tailscale/commit/d00c046b723dff6e3775d7d35f891403ac21a47d Patch 
https://github.com/tailscale/tailscale/releases/tag/v1.38.2 Patch  Release Notes 
https://github.com/tailscale/tailscale/security/advisories/GHSA-vfgq-g5x8-g595 Mitigation  Vendor Advisory 
https://tailscale.com/security-bulletins/#ts-2023-003 Vendor Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-269 Improper Privilege Management Provider acceptance level GitHub, Inc.  

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Change History

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Quick Info

CVE Dictionary Entry:
NVD Published Date:
NVD Last Modified:
GitHub, Inc.