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Privilege escalation in Windows nodes due to Insecure Access Control Lists

Critical
samjustus published GHSA-x7xj-jvwp-97rv Oct 25, 2024

Package

gomod github.com/rancher/rke2 (Go)

Affected versions

>=1.27.0, <1.27.15
>=1.28.0, <1.28.11
>=1.29.0, <1.29.6
>=1.30.0, <1.30.2
<1.31.0

Patched versions

1.27.15
1.28.11
1.29.6
1.30.2
1.31.0

Description

Impact

A vulnerability has been identified whereby RKE2 deployments in Windows nodes have weak Access Control Lists (ACL), allowing BUILTIN\Users or NT AUTHORITY\Authenticated Users to view or edit sensitive files which could lead to privilege escalation.

The affected files include binaries, scripts, configuration and log files:

C:\etc\rancher\node\password
C:\var\lib\rancher\rke2\agent\logs\kubelet.log
C:\var\lib\rancher\rke2\data\v1.**.**-rke2r*-windows-amd64-*\bin\*
C:\var\lib\rancher\rke2\bin\*

This vulnerability is exclusive to RKE2 in Windows environments. Linux environments are not affected by it.

Please consult the associated MITRE ATT&CK - Technique - Exploitation for Privilege Escalation for further information about this category of attack.

Patches

Patched versions include RKE2 1.31.0, 1.30.2, 1.29.6, 1.28.11 and 1.27.15.

Workarounds

Users are advised to do a fresh install of their RKE2 Windows nodes using a patched RKE2 version.
When that is not possible, users can enforce stricter ACLs for all sensitive files affected by this Security Advisory running this PowerShell script as an Administrator on each node.

References

For more information

If you have any questions or comments about this advisory:

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

CVE ID

CVE-2023-32197