Your Docker container? It just walked right out the front door.
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Your Docker container? It just walked right out the front door. 😏
Three vulnerabilities just got patched. November 5th. CVE-2025-31133, CVE-2025-52565, CVE-2025-52881.
Docker, Kubernetes, AWS, Google Cloud. All of them.
Here’s what happened:
→ Attackers can break OUT of your container
→ Get root access on your HOST system
→ Bypass every security layer you thought was protecting you
Let me show you how bad this really is.
The Vulnerabilities
CVE-2025-31133 - Replace one file with a fake link. RunC thinks it’s mounting something safe. Instead? You’re writing directly to the system kernel. Container escape. Done.
RunC masks files using /dev/null. But it doesn’t check if /dev/null is real. Replace it with a symlink to /proc/sys/kernel/core_pattern during startup. Now your container writes directly to kernel config. Write to that file? Arbitrary code execution as root on the host.
CVE-2025-52565 - Trick the console mount during startup. Redirect it before any protections kick in. Write to files that should be locked. Host compromised.
RunC binds /dev/pts/$n to /dev/console for terminal access. Replace /dev/pts/$n with a symlink before runC checks. Redirect the mount to /proc/sysrq-trigger. Everything your container writes to console? Gets written to kernel trigger files. Direct kernel control.
CVE-2025-52881 - This one’s nasty. Bypasses SELinux, bypasses AppArmor. Those security modules everyone says you MUST use? Completely useless here. Write to system triggers. Crash the host or escape completely.
RunC writes Linux Security Module labels to /proc/self/attr/*. These enforce container isolation. Redirect that write to a dummy file? Security policies never get applied. Or redirect to /proc/sys/kernel/core_pattern. Turn a policy write into arbitrary code execution.
These bugs affected virtually every runC version in production. Think about that.
Malicious container image on your system? Attacker breaks out of isolation. Gets root on the host. Accesses all other containers. Steals your data. Installs backdoors. Crashes the server. One command.
And your security layers? SELinux, AppArmor, container policies? They can’t stop these attacks.
What AWS Said
November 5th, AWS drops a security bulletin. They patch everything in 24 hours.
And in that bulletin? This line:
“AWS does not consider containers a security boundary.”
Read that again.
The biggest cloud provider in the world just told you: containers don’t isolate attackers.
They never did.
Containers are good for organizing your applications. Not for keeping attackers out.
What You Need to Do RIGHT NOW
Want to know if you’re vulnerable right now?
Type this:
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If you see anything below 1.2.8, 1.3.3, or 1.4.0-rc.3 → patch immediately.
How to Patch
On Ubuntu/Debian:
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On RHEL/CentOS:
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On Docker: Docker includes runC. Update Docker to get the patched version:
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On Kubernetes: Check with your cloud provider. AWS, Google Cloud, and Azure patched their managed Kubernetes services on November 5th. If you self-host, update your container runtime immediately.
The Container Security Lie
Most people think containers = security. They’re wrong.
Containers are process isolation, not security isolation. They share the kernel with the host. That’s the fundamental problem.
If you need actual security isolation, use virtual machines with separate kernels. Or user namespaces - don’t run containers as root. Or gVisor and Kata Containers for additional isolation layers. Don’t trust containers alone to protect you from malicious code.
Want to Learn More?
Want to learn how to find these vulnerabilities yourself?
My complete ethical hacking course covers Docker exploitation, container escapes, privilege escalation, and 100+ real-world scenarios:
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Video Walkthrough
Want to see how container escapes actually work? I made a whole video breaking this down. Different techniques, same problem: