CVE-2021-31999

Rancher: Privilege escalation vulnerability via malicious Connection header

HIGH

8.8

CVSS Score

Published: July 15, 2021 at 08:55 AM UTC

Updated: June 17, 2026 at 03:52 AM UTC

1 product affected across 1 vendorRancher

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Severity

HIGH8.8

Exploit prediction

EPSS 1%

Description

A Reliance on Untrusted Inputs in a Security Decision vulnerability in Rancher allows users in the cluster to act as others users in the cluster by forging the "Impersonate-User" or "Impersonate-Group" headers. This issue affects: Rancher versions prior to 2.5.9. Rancher versions prior to 2.4.16.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Rancher · Rancher

95%

v < 2.4.162.5.0 ≤ v < 2.5.9Rancher ≤ v < 2.4.16Rancher ≤ v < 2.5.9Rancher

Affected range stops below 2.4.16, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.5.9, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

References (1)

x_refsource_CONFIRMIssue TrackingRelease NotesThird Party Advisory

Source: [email protected]

https://bugzilla.suse.com/show_bug.cgi?id=1187084

CVSS

8.8HIGHsuse

Attack Vector: NETWORK
Complexity: LOW
Privileges: LOW
User Interaction: NONE
Scope: UNCHANGED
Confidentiality: HIGH
Integrity: HIGH
Availability: HIGH

Vector?

Quick Info

StatusMODIFIED

CWE

CWE-807

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