CVE-2021-36776
Steve API proxy impersonation
A Improper Access Control vulnerability in SUSE Rancher allows remote attackers impersonate arbitrary users. This issue affects: SUSE Rancher Rancher versions prior to 2.5.10.
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
CVE List Score used
Steve API proxy impersonation
A Improper Access Control vulnerability in SUSE Rancher allows remote attackers impersonate arbitrary users. This issue affects: SUSE Rancher Rancher versions prior to 2.5.10.
- Record
CVE-2021-36776- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
EUVDEUVD-2024-1211
A Improper Access Control vulnerability in SUSE Rancher allows remote attackers impersonate arbitrary users. This issue affects: SUSE Rancher Rancher versions prior to 2.5.10.
- Record
EUVD-2024-1211- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-03
GitHub AdvisoriesGHSA-gvh9-xgrq-r8hw
Rancher's Steve API Component Improper authorization check allows privilege escalation
Impact
A flaw discovered in Rancher versions from 2.5.0 up to and including 2.5.9 allows an authenticated user to impersonate any user on a cluster through the Steve API proxy, without requiring knowledge of the impersonated user's credentials. This is due to the Steve API proxy not dropping the impersonation header before sending the request to the Kubernetes API. A malicious user with authenticated access to Rancher could use this to impersonate another user with administrator access in Rancher, receiving, then, administrator level access in the cluster.
Patches
Patched versions include releases 2.5.10, 2.6.0 and later versions.
Workarounds
Limit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.
For more information
If you have any questions or comments about this advisory:
- Reach out to SUSE Rancher Security team for security related inquiries.
- Open an issue in Rancher repository.
- Verify our support matrix and product support lifecycle.
- Record
GHSA-gvh9-xgrq-r8hw- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
NVD
A Improper Access Control vulnerability in SUSE Rancher allows remote attackers impersonate arbitrary users. This issue affects: SUSE Rancher Rancher versions prior to 2.5.10.
- Record
CVE-2021-36776- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - CVSS 2.0
- 6.5 Medium
AV:N/AC:L/Au:S/C:P/I:P/A:P - Weakness
- CWE-284
- Updated
- 2026-11-02
OSV
A Improper Access Control vulnerability in SUSE Rancher allows remote attackers impersonate arbitrary users. This issue affects: SUSE Rancher Rancher versions prior to 2.5.10.
- Record
CVE-2021-36776- CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Updated
- 2026-11-02
OSVGHSA-gvh9-xgrq-r8hw
Rancher's Steve API Component Improper authorization check allows privilege escalation
Impact
A flaw discovered in Rancher versions from 2.5.0 up to and including 2.5.9 allows an authenticated user to impersonate any user on a cluster through the Steve API proxy, without requiring knowledge of the impersonated user's credentials. This is due to the Steve API proxy not dropping the impersonation header before sending the request to the Kubernetes API. A malicious user with authenticated access to Rancher could use this to impersonate another user with administrator access in Rancher, receiving, then, administrator level access in the cluster.
Patches
Patched versions include releases 2.5.10, 2.6.0 and later versions.
Workarounds
Limit access in Rancher to trusted users. There is not a direct mitigation besides upgrading to the patched Rancher versions.
For more information
If you have any questions or comments about this advisory:
- Reach out to SUSE Rancher Security team for security related inquiries.
- Open an issue in Rancher repository.
- Verify our support matrix and product support lifecycle.
- Record
GHSA-gvh9-xgrq-r8hw- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-284
- Updated
- 2026-11-02
OSVGO-2024-2771 No score
Rancher's Steve API Component Improper authorization check allows privilege escalation in github.com/rancher/rancher
Rancher's Steve API Component Improper authorization check allows privilege escalation in github.com/rancher/rancher.
NOTE: The source advisory for this report contains additional versions that could not be automatically mapped to standard Go module versions.
(If this is causing false-positive reports from vulnerability scanners, please suggest an edit to the report.)
The additional affected modules and versions are: github.com/rancher/rancher from v2.5.0 before v2.5.10.
- Record
GO-2024-2771- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
github.com/rancher/rancherGo |
2.5.0 to 2.5.9 | 2.5.10 |
github.com/rancher/rancherGo |
2.5.0 up to 2.5.10 | 2.5.10 |
github.com/rancher/rancherGo |
All versions | None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases, published | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-36776 is a high vulnerability (CVSS 8.8) in Rancher, published April 1, 2022. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.12%, the 66th percentile. Fixed in github.com/rancher/rancher 2.5.10.