CVE-2022-4318

Q: What is the severity of CVE-2022-4318?

CVE-2022-4318 has a CVSS score of 7.8 (HIGH). This vulnerability in cri-o allows attackers to inject arbitrary lines into the /etc/passwd file using a specially crafted environment variable. This could enable privilege escalation or unauthorized access to containerized systems. Organizations using vulnerable versions of cri-o for container orchestration are affected.

7.8 HIGH

📋 TL;DR

This vulnerability in cri-o allows attackers to inject arbitrary lines into the /etc/passwd file using a specially crafted environment variable. This could enable privilege escalation or unauthorized access to containerized systems. Organizations using vulnerable versions of cri-o for container orchestration are affected.

💻 Affected Systems

Products:

cri-o

Versions: cri-o versions before 1.25.3, 1.26.0-rc.4, and 1.24.6

Operating Systems: Linux

Default Config Vulnerable: ⚠️ Yes

Notes: Affects systems using cri-o as container runtime, particularly in Kubernetes environments. Requires ability to create or modify containers with crafted environment variables.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Full container escape leading to host compromise, privilege escalation to root, and potential lateral movement across the Kubernetes cluster.

🟠

Likely Case

Privilege escalation within containers, unauthorized access to sensitive container data, and potential manipulation of container user accounts.

🟢

If Mitigated

Limited impact with proper container isolation, minimal container privileges, and restricted environment variable usage.

🌐 Internet-Facing: MEDIUM - Exploitation requires access to container runtime, typically not directly internet-facing but could be exposed through orchestration APIs.

🏢 Internal Only: HIGH - Container runtimes are commonly deployed internally, and successful exploitation could lead to significant internal compromise.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to create containers with malicious environment variables. Public proof-of-concept demonstrates the injection technique.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: cri-o 1.25.3, 1.26.0-rc.4, or 1.24.6

Vendor Advisory: https://access.redhat.com/security/cve/CVE-2022-4318

Restart Required: Yes

Instructions:

1. Update cri-o to version 1.25.3, 1.26.0-rc.4, or 1.24.6. 2. Restart cri-o service. 3. Restart affected containers. 4. Verify no containers are using vulnerable versions.

🔧 Temporary Workarounds

Restrict Environment Variable Usage

linux

Limit environment variables that can be passed to containers and validate them before container creation.

# Configure Kubernetes admission controllers to restrict env vars
# Use Pod Security Standards to limit container capabilities

Implement Container Security Context

linux

Apply security contexts that restrict container privileges and prevent privilege escalation.

# Apply Kubernetes security context:
apiVersion: v1
kind: Pod
metadata:
  name: secure-pod
spec:
  securityContext:
    runAsNonRoot: true
    runAsUser: 1000
  containers:
  - name: app
    securityContext:
      allowPrivilegeEscalation: false
      readOnlyRootFilesystem: true

🧯 If You Can't Patch

Implement strict network policies to isolate cri-o runtime from untrusted networks
Deploy runtime security monitoring to detect /etc/passwd modification attempts

🔍 How to Verify

Check if Vulnerable:

Check cri-o version with: crio --version | grep -E '1\.(24\.([0-5]|5\.[0-5])|25\.([0-2]|2\.[0-2])|26\.0-rc\.[0-3])'

Check Version:

crio --version

Verify Fix Applied:

Verify cri-o version is 1.25.3, 1.26.0-rc.4, or 1.24.6 with: crio --version

📡 Detection & Monitoring

Log Indicators:

Unexpected modifications to /etc/passwd in container logs
Suspicious environment variable names or values in container creation logs
Failed authentication attempts using newly created users

Network Indicators:

Unusual container-to-container communication patterns
Unexpected outbound connections from cri-o runtime

SIEM Query:

source="container_logs" AND ("passwd modification" OR "useradd" OR "usermod")

📊 Metadata

CVE ID: CVE-2022-4318

CVSS v3 Score: 7.8 (HIGH)

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

CWE: CWE-538

Published: September 25, 2023

Last Updated: November 21, 2024

🔗 References

https://access.redhat.com/errata/RHSA-2023:1033 Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:1503 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2022-4318 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2152703 Issue Tracking,Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:1033 Third Party Advisory
https://access.redhat.com/errata/RHSA-2023:1503 Third Party Advisory
https://access.redhat.com/security/cve/CVE-2022-4318 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2152703 Issue Tracking,Third Party Advisory

📋 TL;DR

💻 Affected Systems

📦 What is this software?

Cri O by Kubernetes

Extra Packages For Enterprise Linux by Fedoraproject

Fedora by Fedoraproject

Fedora by Fedoraproject

Openshift Container Platform For Arm64 by Redhat

Openshift Container Platform For Arm64 by Redhat

Openshift Container Platform For Arm64 by Redhat

Openshift Container Platform For Linuxone by Redhat

Openshift Container Platform For Linuxone by Redhat

Openshift Container Platform For Linuxone by Redhat

Openshift Container Platform For Power by Redhat

Openshift Container Platform For Power by Redhat

Openshift Container Platform For Power by Redhat

Openshift Container Platform Ibm Z Systems by Redhat

Openshift Container Platform Ibm Z Systems by Redhat

Openshift Container Platform Ibm Z Systems by Redhat

⚠️ Risk & Real-World Impact

Worst Case

Likely Case

If Mitigated

🎯 Exploit Status

🛠️ Fix & Mitigation

✅ Official Fix

Instructions:

🔧 Temporary Workarounds

Restrict Environment Variable Usage

Implement Container Security Context

🧯 If You Can't Patch

🔍 How to Verify

Check if Vulnerable:

Check Version:

Verify Fix Applied:

📡 Detection & Monitoring

Log Indicators:

Network Indicators:

SIEM Query:

📊 Metadata

🔗 References

📤 Share & Export

🔗 Related Vulnerabilities