8.0
HIGH
CVE-2023-28436
Tailscale FreeBSD SSH Privilege Escalation Vulnerability
Description

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.

INFO

Published Date :

March 23, 2023, 8:15 p.m.

Last Modified :

Nov. 21, 2024, 7:55 a.m.

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

2.1
Affected Products

The following products are affected by CVE-2023-28436 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Tailscale tailscale

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-28436 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2023-28436 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://github.com/tailscale/tailscale/commit/d00c046b723dff6e3775d7d35f891403ac21a47d
    Added Reference https://github.com/tailscale/tailscale/releases/tag/v1.38.2
    Added Reference https://github.com/tailscale/tailscale/security/advisories/GHSA-vfgq-g5x8-g595
    Added Reference https://tailscale.com/security-bulletins/#ts-2023-003
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Changed Description 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. 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.
  • Initial Analysis by [email protected]

    Mar. 31, 2023

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://github.com/tailscale/tailscale/commit/d00c046b723dff6e3775d7d35f891403ac21a47d No Types Assigned https://github.com/tailscale/tailscale/commit/d00c046b723dff6e3775d7d35f891403ac21a47d Patch
    Changed Reference Type https://github.com/tailscale/tailscale/releases/tag/v1.38.2 No Types Assigned https://github.com/tailscale/tailscale/releases/tag/v1.38.2 Patch, Release Notes
    Changed Reference Type https://github.com/tailscale/tailscale/security/advisories/GHSA-vfgq-g5x8-g595 No Types Assigned https://github.com/tailscale/tailscale/security/advisories/GHSA-vfgq-g5x8-g595 Mitigation, Vendor Advisory
    Changed Reference Type https://tailscale.com/security-bulletins/#ts-2023-003 No Types Assigned https://tailscale.com/security-bulletins/#ts-2023-003 Vendor Advisory
    Added CPE Configuration OR *cpe:2.3:a:tailscale:tailscale:*:*:*:*:*:*:*:* versions from (including) 1.34 up to (excluding) 1.38.2
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-28436 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-28436 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.04 }} -0.00%

score

0.05674

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability