CVE-2021-38182 – CVE-2021-38182 is an input validation vulnerabi... (How to Fix)

Q: What is the severity of CVE-2021-38182?

CVE-2021-38182 has a CVSS score of 8.8 (HIGH). CVE-2021-38182 is an input validation vulnerability in Kyma that allows authenticated users to escalate privileges by manipulating headers. This can lead to complete cluster compromise. Affected systems are Kyma deployments with vulnerable versions.

📋 TL;DR

CVE-2021-38182 is an input validation vulnerability in Kyma that allows authenticated users to escalate privileges by manipulating headers. This can lead to complete cluster compromise. Affected systems are Kyma deployments with vulnerable versions.

💻 Affected Systems

Products:

Kyma

Versions: Versions prior to 2.0.0

Operating Systems: All platforms running Kyma

Default Config Vulnerable: ⚠️ Yes

Notes: Requires authenticated user access to Kyma API.

📦 What is this software?

Kyma by Kyma Project

View all CVEs affecting Kyma →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete cluster takeover with administrative privileges, allowing data exfiltration, service disruption, and lateral movement.

🟠

Likely Case

Privilege escalation leading to unauthorized access to sensitive resources and potential data breaches.

🟢

If Mitigated

Limited impact with proper network segmentation and least privilege access controls in place.

🌐 Internet-Facing: HIGH if Kyma API is exposed to the internet, as authenticated users can exploit remotely.

🏢 Internal Only: HIGH as authenticated internal users can exploit to gain elevated privileges.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires authenticated access but is straightforward once authenticated.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 2.0.0 and later

Vendor Advisory: https://github.com/kyma-project/kyma/security/advisories/GHSA-2vjp-5q24-hqjv

Restart Required: Yes

Instructions:

1. Update Kyma to version 2.0.0 or later. 2. Follow Kyma upgrade documentation. 3. Restart Kyma components.

🔧 Temporary Workarounds

Restrict API Access

all

Limit access to Kyma API to trusted users only using network controls.

Implement Header Validation

all

Add custom validation to reject unexpected headers at proxy level.

🧯 If You Can't Patch

Implement strict network segmentation to isolate Kyma from other critical systems.
Enforce least privilege access controls and monitor for unusual header manipulation in logs.

🔍 How to Verify

Check if Vulnerable:

Check Kyma version; if below 2.0.0, it is vulnerable.

Check Version:

kubectl get deployment -n kyma-system -o jsonpath='{.items[*].spec.template.spec.containers[*].image}' | grep kyma

Verify Fix Applied:

Confirm Kyma version is 2.0.0 or higher after update.

📡 Detection & Monitoring

Log Indicators:

Unusual header values in API requests
Privilege escalation attempts in audit logs

Network Indicators:

Abnormal API calls to Kyma endpoints with custom headers

SIEM Query:

source="kyma" AND (header_manipulation OR privilege_escalation)

📊 Metadata

CVE ID: CVE-2021-38182

CVSS v3 Score: 8.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-20

Published: December 14, 2021

Last Updated: November 21, 2024

🔗 References

https://github.com/kyma-project/kyma/security/advisories/GHSA-2vjp-5q24-hqjv Third Party Advisory
https://wiki.scn.sap.com/wiki/display/PSR/SAP+Security+Patch+Day+-+December+2021 Not Applicable
https://github.com/kyma-project/kyma/security/advisories/GHSA-2vjp-5q24-hqjv Third Party Advisory
https://wiki.scn.sap.com/wiki/display/PSR/SAP+Security+Patch+Day+-+December+2021 Not Applicable

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