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🛡️ CVE-2021-25320 — rancher

🔴 CVSS 9.5 — Critical ✅ No Known Exploit CWE-284 OSV
9.5
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

Rancher cloud credentials can be used through proxy API by users without access

A vulnerability was discovered in Rancher 2.2.0 through the aforementioned patched versions, where cloud credentials weren't being properly validated through the Rancher API. Specifically through a proxy designed to communicate with cloud providers. Any Rancher user that was logged-in and aware of a cloud-credential ID that was valid for a given cloud provider, could call that cloud provider's API through the proxy API, and the cloud-credential would be attached. The exploit is limited to valid Rancher users. There is not a direct mitigation outside of upgrading to the patched Rancher versions.

How this vulnerability can be exploited

This issue can be reached over the network, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is changed, meaning a successful attack can affect components beyond the vulnerable one. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Network — reachable from anywhere that can route to the service.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Changed — a successful attack reaches components beyond the vulnerable one.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Weakness class

CVE-2021-25320 is classified as CWE-284: Improper Access Control. The software does not restrict an action to the actors that should be allowed to perform it.

Affected software

CVE-2021-25320 is recorded against 1 package.

  • github.com/rancher/rancher

Timeline and source

Published on 10 March 2026 and last revised on 10 July 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.

References

github.com (Advisory)
nvd.nist.gov (Advisory)
bugzilla.suse.com (Web)

Other advisories for this package

github.com/rancher/rancher has other advisories on record. If you are patching this one, these are worth checking on the same host:

Same weakness in other software

These advisories are the same class of weakness (CWE-284: Improper Access Control) in other software:

Details

Severity CRITICAL
CVSS Score 9.5
CVSS Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE CWE-284
Public Exploit ✅ No
Source OSV
Published 2026-03-10
Updated 2026-08-20
Modified 2026-07-10
Fix URL N/A

Affected Packages

Software From version Fixed in
github.com/rancher/rancher — —

Similar Threats

Exploit Protection

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ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the vulnerabilities listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.

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