disconnect3d

Container security notes

Internet references

Kernel and architecture

• namespaces - overview of Linux namespaces http://man7.org/linux/man-pages/man7/namespaces.7.html

• mount_namespaces - overview of Linux mount namespaces

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# dotfile: ~/.gitconfig
# vim: ft=gitconfig

[alias]
    ci = commit
    co = checkout
    br = branch
    st = status
    cp = cherry-pick
    subup = submodule update --init --recursive

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In [3]: from collections import UserDict, defaultdict

In [4]: class A(UserDict):
   ...:     def __getitem__(self, key):
   ...:         if key not in self:
   ...:             self[key] = defaultdict(lambda: A())
   ...:         return super().__getitem__(key)
   ...:

In [6]: a = A()

disconnect3d

Confidence CTF 2019 - Rethon task writeup (draft)

TLDR:

• We got a task file that was a result of python3.7 -m dis task.py - it had 7000+ lines, you can see it below
• I created a genpyc.py that parsed it and assembled Python's code objects back to life (e.g. function's/module's .__code__.co_* fields)
• It turned out that we can't decompile the resulting code objects or pyc via uncompyle6 or some other decompilers I tried
• But we could dis.dis it to compare the disassembly and we could exec it or launch it via python3.7 sol.pyc

A caveat here - while the resulting pyc can be launched with a standard Python, we will get:

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dc@dc:~/fbctf$ sshpass -p "osquerygame" ssh [email protected] -p2222
Using a virtual database. Need help, type '.help'
W0603 00:15:46.326594 23481 challenge.cpp:633] Welcome to the osquery farm simulator extension. You have 5 days to make your farm successful.
osquery> select * from farm a, farm b where a.action="move"
    ...> AND
    ...> a.src=((INSTR(b.farm, (select emoji from farm_emoji where meaning="sheep"))-34)/18 << 4) +
    ...> ((INSTR(b.farm, (select emoji from farm_emoji where meaning="sheep"))-34)%18 - 3)
    ...> AND
    ...> a.dst=(((INSTR(b.farm, (select emoji from farm_emoji where meaning="pig"))-34)/18 - 1) << 4) +

disconnect3d

#include <tunables/global>


profile docker-default flags=(attach_disconnected,mediate_deleted) {

  #include <abstractions/base>


  network,
  capability,

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import ctypes


def calc(v):
    return getattr(v, 'value', v)


def gen_c_type(name, ctype, floordiv=True):
    class Type(ctype):
        def __add__(self, other):

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import ctypes

class MyStruct(ctypes.LittleEndianStructure):
    _fields_ = (
        ('x', ctypes.c_float),
        ('y', ctypes.c_float),
        ('velocity', ctypes.c_int32),
        ('weight', ctypes.c_uint32)
    )

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// kod zrodlowy do zadania Production
// z Teaser Dragon CTF 2018
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <unistd.h>
#include <cassert>

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#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <unistd.h>

#include <cassert>
#include <cstdio>