CVE-2025-9276
📋 TL;DR
CVE-2025-9276 allows remote attackers to bypass authentication on systems using vulnerable Cockroach Labs cockroach-k8s-request-cert container images due to a blank root password in the shadow file. This affects organizations running the affected container image in Kubernetes environments. Attackers can gain root access without credentials.
💻 Affected Systems
- Cockroach Labs cockroach-k8s-request-cert container image
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with root access, allowing data theft, service disruption, and lateral movement within the Kubernetes cluster.
Likely Case
Unauthorized root access to the container, enabling privilege escalation and potential compromise of the entire containerized application.
If Mitigated
Limited impact if containers run with minimal privileges and network access is restricted, though authentication bypass remains possible.
🎯 Exploit Status
Exploitation requires network access to the container and knowledge of the vulnerability; trivial to exploit once identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Cockroach Labs advisory for specific fixed version
Vendor Advisory: https://www.cockroachlabs.com/docs/advisories/ (check for specific advisory)
Restart Required: Yes
Instructions:
1. Check Cockroach Labs advisory for fixed version. 2. Update to patched container image. 3. Redeploy containers in Kubernetes. 4. Verify no vulnerable containers remain.
🔧 Temporary Workarounds
Set root password manually
linuxManually set a strong password for root user in the container's shadow file
docker exec <container> passwd root
kubectl exec <pod> -- passwd root
Restrict network access
allUse network policies to limit access to vulnerable containers
🧯 If You Can't Patch
- Isolate vulnerable containers using network segmentation and firewall rules.
- Monitor for unauthorized access attempts and root login activity.
🔍 How to Verify
Check if Vulnerable:
Check if root password field is empty in /etc/shadow: docker exec <container> grep '^root::' /etc/shadowCheck Version:
docker images | grep cockroach-k8s-request-certVerify Fix Applied:
Verify root has password set: docker exec <container> grep '^root:' /etc/shadow | grep -v '::'📡 Detection & Monitoring
Log Indicators:
- Successful root login without password
- Authentication bypass attempts in container logs
Network Indicators:
- Unexpected SSH or authentication traffic to container ports
SIEM Query:
source="container_logs" AND "root login" AND "password"