Vulnerabilities in pkg:golang/tailscale.com

PACKAGE
Advisory Identifier: GHSA-vfgq-g5x8-g595
Advisory Summary

CVE-2023-28436 is a MODERATE (CVSS 5.7) non-interactive tailscale ssh sessions on vulnerability (CWE-269: Improper Privilege Management) affecting Tailscale.com libraries in the Go ecosystem. The issue involves non-interactive tailscale ssh sessions on freebsd may use the effective group id of the tailscaled process. Remediation is available by upgrading affected packages to version 1.38.2.

2 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:golang/tailscale.com

2 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:golang/tailscale.com. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-vfgq-g5x8-g595 CVE-2023-28436 MODERATE Non-interactive Tailscale SSH sessions on FreeBSD may use the effective group ID of the tailscaled process
GHSA-vqp6-rc3h-83cp CVE-2022-41924 CRITICAL Tailscale Windows daemon is vulnerable to RCE via CSRF

CVE-2023-28436 at a Glance

CVE Identifier CVE-2023-28436
GHSA Identifier GHSA-vfgq-g5x8-g595
Severity MODERATE
CVSS v3.1 Base Score 5.7
CWE Classification CWE-269: Improper Privilege Management
Affected Product Tailscale.com
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 5.7

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N).

Attack Vector Adjacent (AV:A)
Attack Complexity Low (AC:L)
Privileges Required High (PR:H)
User Interaction Required (UI:R)
Scope Changed (S:C)
Confidentiality High (C:H)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2023-28436

To remediate this vulnerability, upgrade all affected Tailscale.com dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

tailscale.com fixed: 1.38.2
Upgrade tailscale.com to 1.38.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for tailscale.com

How to Check if You Are Affected

To determine whether your application is affected by CVE-2023-28436, inspect your project dependencies for Tailscale.com:

inspect dependencies for tailscale.com

Analyze the terminal output to locate any version of Tailscale.com in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.38.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-269: Improper Privilege Management, where the product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. In Tailscale.com, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability identified in the implementation of Tailscale SSH in FreeBSD allowed commands to be run with a higher privilege group ID than that specified by Tailscale SSH access rules. **Affected platforms**: FreeBSD **Patched Tailscale client versions**: v1.38.2 or later ### What happened? 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. ### Who is affected? 9 tailnets with 22 FreeBSD nodes running Tailscale SSH since Tailscale v1.34 (released on 2022-12-04) may have had Tailscale SSH sessions with a higher privilege group ID than that specified in Tailscale SSH access rules. We have notified the affected organizations where we have [security contacts](https://tailscale.com/kb/1224/contact-preferences/#setting-the-security-issues-email). ### What is the impact? 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. ### What do I need to do? If you are running Tailscale on FreeBSD, upgrade to v1.38.2 or later to remediate the issue. Admins of a tailnet can view [FreeBSD nodes with unpatched versions](https://login.tailscale.com/admin/machines?q=version%3A%3C1.38.2+freebsd) in the admin console. To update the local ports tree in advance of what's available upstream, you can: 1. `cd /usr/ports/security/tailscale` 2. edit the Makefile to set `PORTVERSION` to `1.38.2` 3. `make makesum` 4. `make install` Tailscale SSH on other platforms is not affected. ### Credits We would like to thank [Ryan Belgrave](https://www.linkedin.com/in/rbelgrave/) for reporting this issue. ### References * [TS-2023-003](https://tailscale.com/security-bulletins/#ts-2023-003)

CVE-2023-28436 Affected Tailscale.com Versions

1 component(s)
Fixed Versions:
1.38.2
Product / Package Ecosystem Affected Versions Fixed Version
tailscale.com
Go
≥ 1.34.0
< 1.38.2
1.38.2

References

Frequently Asked Questions

What is CVE-2023-28436?
CVE-2023-28436 is a security vulnerability in Tailscale.com involving Non-interactive Tailscale SSH sessions on FreeBSD may use the effective group ID of the tailscaled process under CWE-269: Improper Privilege Management.
Which Tailscale.com versions are affected?
Affected versions include releases prior to 1.38.2 across affected packages: tailscale.com.
What version fixes CVE-2023-28436?
Upgrading to 1.38.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is tailscale.com affected?
Yes, tailscale.com is affected in releases prior to 1.38.2. Upgrade your dependency to 1.38.2 or later.
What is the CVSS score of CVE-2023-28436?
CVE-2023-28436 has a CVSS v3.1 base score of 5.7 (MODERATE) with vector string CVSS:3.0/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2023-28436?
CVE-2023-28436 is classified under CWE-269: Improper Privilege Management (The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.).
How can I check Go dependencies for CVE-2023-28436?
Run the dependency tree command: 'inspect dependencies for tailscale.com'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-vfgq-g5x8-g595",
  "modified" : "2023-03-23T22:09:19Z",
  "published" : "2023-03-23T19:58:23Z",
  "aliases" : [ "CVE-2023-28436" ],
  "summary" : "Non-interactive Tailscale SSH sessions on FreeBSD may use the effective group ID of the tailscaled process",
  "details" : "A vulnerability identified in the implementation of Tailscale SSH in FreeBSD allowed commands to be run with a higher privilege group ID than that specified by Tailscale SSH access rules.\n\n**Affected platforms**: FreeBSD\n\n**Patched Tailscale client versions**: v1.38.2 or later\n\n### What happened?\nA 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.\n\n### Who is affected?\n9 tailnets with 22 FreeBSD nodes running Tailscale SSH since Tailscale v1.34 (released on 2022-12-04) may have had Tailscale SSH sessions with a higher privilege group ID than that specified in Tailscale SSH access rules.\n\nWe have notified the affected organizations where we have [security contacts](https://tailscale.com/kb/1224/contact-preferences/#setting-the-security-issues-email).\n\n### What is the impact?\nTailscale 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:\n* The destination node was a FreeBSD device with Tailscale SSH enabled;\n* Tailscale SSH access rules permitted access for non-root users; and\n* A non-interactive SSH session was used.\n\n### What do I need to do?\nIf you are running Tailscale on FreeBSD, upgrade to v1.38.2 or later to remediate the issue. Admins of a tailnet can view [FreeBSD nodes with unpatched versions](https://login.tailscale.com/admin/machines?q=version%3A%3C1.38.2+freebsd) in the admin console.\n\nTo update the local ports tree in advance of what's available upstream, you can:\n\n1. `cd /usr/ports/security/tailscale`\n2. edit the Makefile to set `PORTVERSION` to `1.38.2`\n3. `make makesum`\n4. `make install`\n\nTailscale SSH on other platforms is not affected.\n\n### Credits\nWe would like to thank [Ryan Belgrave](https://www.linkedin.com/in/rbelgrave/) for reporting this issue.\n\n### References\n* [TS-2023-003](https://tailscale.com/security-bulletins/#ts-2023-003)\n\n\n",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:A/AC:L/PR:H/UI:R/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "tailscale.com"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.34.0"
      }, {
        "fixed" : "1.38.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/tailscale/tailscale/security/advisories/GHSA-vfgq-g5x8-g595"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-28436"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tailscale/tailscale/commit/d00c046b723dff6e3775d7d35f891403ac21a47d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/tailscale/tailscale"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tailscale/tailscale/releases/tag/v1.38.2"
  }, {
    "type" : "WEB",
    "url" : "https://tailscale.com/security-bulletins/#ts-2023-003"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-269" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-03-23T19:58:23Z",
    "nvd_published_at" : "2023-03-23T20:15:00Z"
  }
}