CVE-2018-20321
Access Control Bypass
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
CVE-2018-20321- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 9.0 High
AV:N/AC:L/Au:S/C:C/I:C/A:C - Weakness
- CWE-668
- Updated
- 2026-11-02
CVE List No score
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
CVE-2018-20321- Updated
- 2026-11-02
EUVDEUVD-2021-1305 No score
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
EUVD-2021-1305- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-9qq2-xhmc-h9qr
Access Control Bypass
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
GHSA-9qq2-xhmc-h9qr- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-288, CWE-668
- Updated
- 2026-11-02
OSV
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
CVE-2018-20321- CVSS 3.0
- 8.8 High
CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-9qq2-xhmc-h9qr
Access Control Bypass
An issue was discovered in Rancher 2 through 2.1.5. Any project member with access to the default namespace can mount the netes-default service account in a pod, and then use that pod to execute administrative privileged commands against the k8s cluster. This could be mitigated by isolating the default namespace in a separate project, where only cluster admins can be given permissions to access. As of 2018-12-20, this bug affected ALL clusters created or imported by Rancher.
- Record
GHSA-9qq2-xhmc-h9qr- CVSS 3.1
- 4.2 Medium
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:L/A:N - Weakness
- CWE-288, CWE-668
- Updated
- 2026-11-02
OSVGO-2022-0644 No score
Access Control Bypass in github.com/rancher/rancher
Access Control Bypass in github.com/rancher/rancher
- Record
GO-2022-0644- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/rancher/rancherGo |
2.0.0 up to 2.1.6 | 2.1.6 |
github.com/rancher/rancherGo |
2.0.0+incompatible up to 2.1.6+incompatible | 2.1.6+incompatible |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2018-20321 is a high vulnerability (CVSS 8.8) in Suse Rancher, published April 10, 2019. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.77%, the 78th percentile. Fixed in github.com/rancher/rancher 2.1.6.
References
rancher.com/blog/2019/2019-01-29-explaining-security-vulnerabilities-addressed-in-rancher-v2-1-6-and-v2-0-11
forums.rancher.com/c/announcements
nvd.nist.gov/vuln/detail/CVE-2018-20321
github.com/rancher/rancher/commit/6ea187fcc2309d5a7a14ed47de5688bf6573f448