andreyryabtsev

adolli

如何使用python3逃逸沙箱，获得进程上下文权限提升

最近突发奇想，想对所掌握的python知识进行总结一下，目前其实还停留在python层面如何使用，还没有深入到虚拟机部分，如果下面有哪些错误，欢迎指出。

背景

OJ(Online judge, 在线编程测评提交代码到后台运行检查)网站一般都允许各种各样的代码提交，其中很有可能包含python3，于是决定尝试通过python3的代码执行，进行沙箱逃逸，以及绕过各种限制。

我随便找了一个OJ网站，这个站点的python3有如下限制

grantseltzer

//go:cgo_import_dynamic libc_res_search res_search "/usr/lib/libSystem.B.dylib"

willprice

Install OpenCV 4.1.2 on Raspbian Buster

$ chmod +x *.sh
$ ./download-opencv.sh
$ ./install-deps.sh
$ ./build-opencv.sh
$ cd ~/opencv/opencv-4.1.2/build
$ sudo make install

ZLOY5

PseudoRandomDistribution = {}
PseudoRandomDistribution.__index = PseudoRandomDistribution

function PseudoRandomDistribution:New(nChance) 
	local obj = { 
		counter = 0,
		chance = nChance,
		const = self:CalculateConstant(nChance)
	}
	setmetatable(obj,self)

codeinthehole

How to share a folder with a docker container on OSX

Mounting shared folders between OSX and the docker container is tricky due to the intermediate boot2docker VM. You can't use the usual docker -v option as the docker server knows nothing about the OSX filesystem - it can only mount folders from the boot2docker filesystem. Fortunately, you can work around this using SSHFS.

hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

burke

ruby-1.9.3-p327 cumulative performance patch for rbenv

This installs a patched ruby 1.9.3-p327 with various performance improvements and a backported COW-friendly GC, all courtesy of funny-falcon.

Requirements

• rbenv
• ruby-build

You will also need a C Compiler. If you're on Linux, you probably already have one or know how to install one. On OS X, you should install XCode, and brew install autoconf using homebrew.

johnreilly

#This is psudocode, but should be an okay example...

# Step 1: require rails' environment
require 'path/to/config/environment'

# Step 2: add rails app to cascade:

run Rack::Cascade.new([
  rack_app1,
  MyRailsApp::Application, # Place rails in the cascade where you need it