CVE-2022-2385
📋 TL;DR
CVE-2022-2385 is a privilege escalation vulnerability in aws-iam-authenticator where allow-listed IAM identities can modify their usernames to gain unauthorized Kubernetes cluster access. This affects Kubernetes clusters using aws-iam-authenticator for AWS IAM authentication. Attackers could gain cluster administrator privileges if they have an allow-listed IAM identity.
💻 Affected Systems
- aws-iam-authenticator
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full cluster compromise allowing attackers to deploy malicious pods, exfiltrate sensitive data, or disrupt cluster operations with administrative privileges.
Likely Case
Unauthorized access to Kubernetes resources, potential data exposure, and privilege escalation within the cluster.
If Mitigated
Limited impact with proper network segmentation, minimal IAM permissions, and monitoring in place.
🎯 Exploit Status
Exploitation requires an allow-listed IAM identity and knowledge of the vulnerability. Public proof-of-concept exists in GitHub issues.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.5.9 and later
Vendor Advisory: https://github.com/kubernetes-sigs/aws-iam-authenticator/security/advisories/GHSA-8jvj-5j3x-9j9j
Restart Required: Yes
Instructions:
1. Update aws-iam-authenticator to version 0.5.9 or later. 2. Replace the authenticator binary in your cluster. 3. Restart the authenticator pods/daemonsets. 4. Verify the new version is running.
🔧 Temporary Workarounds
Restrict IAM Identity Access
allTemporarily remove or restrict IAM identities from allow-lists to only essential users.
# Review and update aws-iam-authenticator configmap to remove non-essential IAM ARNs
kubectl edit configmap -n kube-system aws-iam-authenticator
Network Segmentation
allRestrict network access to aws-iam-authenticator endpoints to trusted sources only.
# Implement network policies or security groups to limit access
# Example: Restrict to specific IP ranges or VPCs
🧯 If You Can't Patch
- Implement strict IAM role and user auditing to detect suspicious modifications
- Enable enhanced Kubernetes audit logging and monitor for unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check aws-iam-authenticator version: kubectl get pods -n kube-system -l app=aws-iam-authenticator -o jsonpath='{.items[*].spec.containers[*].image}'Check Version:
kubectl get pods -n kube-system -l app=aws-iam-authenticator -o jsonpath='{.items[*].spec.containers[*].image}'Verify Fix Applied:
Verify version is 0.5.9 or later: kubectl get pods -n kube-system -l app=aws-iam-authenticator -o jsonpath='{.items[*].spec.containers[*].image}' | grep -E '0\.5\.9|0\.6|0\.7'📡 Detection & Monitoring
Log Indicators:
- Unexpected IAM identity modifications in AWS CloudTrail
- Unauthorized Kubernetes API requests from modified usernames
- aws-iam-authenticator logs showing username manipulation
Network Indicators:
- Unusual authentication requests to aws-iam-authenticator endpoints
- Traffic from unexpected sources to Kubernetes API server
SIEM Query:
source="aws-cloudtrail" AND eventName="UpdateUser" OR source="kubernetes-audit" AND verb="create" AND objectRef.resource="pods" AND user.username CONTAINS "modified"