Andrew Zhilin zoon

Write-up

A warning to Roblox developers about a powerful exploit primitive. In this, I will detail the research I’ve conducted into this attack vector and walk you through how you as a developer, can protect against exploits with primitives like this.

DataStoreService lets you store data that needs to persist between sessions, such as items in a player’s inventory or skill points. Data stores are consistent per experience, so any place in an experience can access and change the same data, including places on different servers.

By default, experiences tested in Studio cannot access data stores, so you must first enable API services. You will need to do this to test the vulnerabilities.

The idea I wanted to explore when pondering the above question was; can we exploit remotes to prevent data from saving? It is easy to blame the developer for not protecting themselves against such a simple exploit but it ends up being more complicated than that. I found plenty of examples of these vulnerabilities occurring

Using Exp for zooming

One of the things I’m happiest to have learned in the past few months is a great use for Log + Exp in games when zooming in and out.

You may have already know that linear speeds work horribly for zooming, e.g.:

void Update() {
    scale = scale + speed * Time.deltaTime;
}

	-- Given a knot sequence p[1<=i<=n], solve for a sequence of cubic
	-- splines s[1<=i<=n-1] such that the square of acceleration is minimized.

	local gamma = {
	0.50000000000000000, 0.28571428571428571, 0.26923076923076923, 0.26804123711340206,
	0.26795580110497238, 0.26794966691339748, 0.26794922649742166, 0.26794919487697295,
	0.26794919260672685, 0.26794919244373052, 0.26794919243202791, 0.26794919243118770,
	0.26794919243112737, 0.26794919243112304, 0.26794919243112273, 0.26794919243112271,
	}
	local gammaLimit = gamma[#gamma]

	local RunService = game:GetService("RunService")

	-- compile an oriented bounding box into a scaled CFrame
	local function compileBBox(cframe: CFrame, size: Vector3)
	return CFrame.fromMatrix(
	cframe.Position,
	cframe.XVector/size.X,
	cframe.YVector/size.Y,
	cframe.ZVector/size.Z
	):Inverse()

	@rem update-unity-compiler.cmd
	@rem start in */[email protected] folder
	@echo off

	@rem NOTE: FIND.EXE can clash with git/msys/cygwin's find
	for %%a in (%ComSpec%) do set __system=%%~dpa
	%__system%FIND.EXE /i "com.unity.incrementalcompiler" package.json 1> NUL
	if %errorlevel% neq 0 goto :not_found

	nuget install Microsoft.Net.Compilers -verbosity quiet

	// When creating shaders for Universal Render Pipeline you can you the ShaderGraph which is super AWESOME!
	// However, if you want to author shaders in shading language you can use this teamplate as a base.
	// Please note, this shader does not necessarily match perfomance of the built-in URP Lit shader.
	// This shader works with URP 7.1.x and above
	Shader "Universal Render Pipeline/Custom/Physically Based Example"
	{
	Properties
	{
	// Specular vs Metallic workflow
	[HideInInspector] _WorkflowMode("WorkflowMode", Float) = 1.0

	/// Used to draw custom inspectors for unrecognised file types, which Unity imports as "DefaultAsset"
	/// To do this, create a new editor class extending DefaultAssetInspector
	/// Return true in the IsValid function if the file extension of the file matches the type you'd like to draw.
	/// The DefaultAssetEditor class will then hold a reference to the new instance of your editor class and call the appropriate methods for drawing.
	/// An example can be found at the bottom of the file.

	using UnityEngine;
	using UnityEditor;
	using System;
	using System.IO;

	/*******************************************************************************
	*
	* A minimal Forth compiler in C
	* By Leif Bruder <leifbruder@gmail.com> http://defineanswer42.wordpress.com
	* Release 2014-04-04
	*
	* Based on Richard W.M. Jones' excellent Jonesforth sources/tutorial
	*
	* PUBLIC DOMAIN
	*