What is the CVSS score of CVE-2023-28436?

CVE-2023-28436 has a CVSS 3.1 base score of 8.0 (High). CVSS vector: CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. EPSS exploitation probability: 0.5%.

Is there a patch available for CVE-2023-28436?

Yes, a patch is available for CVE-2023-28436. Update the affected software to the latest version immediately.

Tailscale CVE-2023-28436

HIGH

Improper Privilege Management (CWE-269)

2023-03-23 security-advisories@github.com

Privilege Escalation Tailscale

8.0

CVSS 3.1 · NVD

Severity by source

NVD PRIMARY

8.0 HIGH

AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Primary rating from NVD · only source for this CVE.

CVSS VectorNVD

CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Adjacent

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Lifecycle Timeline

CVE Published

Mar 23, 2023 - 20:15 nvd

HIGH 8.0

DescriptionNVD

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.

AnalysisAI

Tailscale is software for using Wireguard and multi-factor authentication (MFA). Rated high severity (CVSS 8.0), this vulnerability is low attack complexity. This Improper Privilege Management vulnerability could allow attackers to escalate privileges to gain unauthorized elevated access.

Technical ContextAI

This vulnerability is classified as Improper Privilege Management (CWE-269), which allows attackers to escalate privileges to gain unauthorized elevated access. 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. Affected products include: Tailscale. Version information: version 1.34.0.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply principle of least privilege, validate privilege transitions, implement proper role separation.