paj28

Unicode XSS via Combining Characters

Most application security practitioners are familiar with Unicode XSS, which typically arises from the Unicode character fullwidth-less-than-sign. It’s not a common vulnerability but does occasionally appear in applications that otherwise have good XSS protection. In this blog I describe another variant of Unicode XSS that I have identified, using combining characters. I’ve not observed this in the wild, so it’s primarily of theoretical concern. But the scenario is not entirely implausible and I’ve not otherwise seen this technique discussed, so I hope this is useful.

Recap of Unicode XSS

Lab: https://4t64ubva.xssy.uk/

A quick investigation of the lab shows that it is echoing the name parameter, and performing HTML escaping:

leesh3288

Sandbox Escape in [email protected] via custom inspect function

Summary

In vm2 for versions up to 3.9.19, Node.js custom inspect function allows attackers to escape the sandbox and run arbitrary code.

Proof of Concept

leesh3288

Sandbox Escape in [email protected] via Promise[@@species]

Summary

In vm2 for versions up to 3.9.19, Promise handler sanitization can be bypassed with @@species accessor property allowing attackers to escape the sandbox and run arbitrary code.

Proof of Concept

irazasyed

Using Gmail SMTP with Cloudflare Email Routing: Step-by-Step Guide

Learn how to send emails through Gmail SMTP with Cloudflare Email Routing in this comprehensive guide.

Step 1: Enable 2-Factor Authentication

To proceed with this method, ensure that you have enabled two-factor authentication for your Google account. If you haven't done so already, you can follow the link to set it up → Enable 2FA in your Google account.

Step 2: Create an App Password for Mail

leesh3288

Sandbox Escape in [email protected]

Summary

There exists a vulnerability in exception sanitization of vm2 for versions up to 3.9.16, allowing attackers to raise an unsanitized host exception inside handleException() which can be used to escape the sandbox and run arbitrary code in host context.

Proof of Concept

loknop

Solving "includer's revenge" from hxp ctf 2021 without controlling any files

The challenge

The challenge was to achieve RCE with this file:

<?php ($_GET['action'] ?? 'read' ) === 'read' ? readfile($_GET['file'] ?? 'index.php') : include_once($_GET['file'] ?? 'index.php');

Some additional hardening was applied to the php installation to make sure that previously known solutions wouldn't work (for further information read this writeup from the challenge author).

I didn't solve the challenge during the competition - here is a writeup from someone who did - but since the idea I had differed from the techniques used in the published writeups I read (and I thought it was cool :D), here is my approach.

0xabad1dea

Risk Assessment of GitHub Copilot

0xabad1dea, July 2021

this is a rough draft and may be updated with more examples

GitHub was kind enough to grant me swift access to the Copilot test phase despite me @'ing them several hundred times about ICE. I would like to examine it not in terms of productivity, but security. How risky is it to allow an AI to write some or all of your code?

Ultimately, a human being must take responsibility for every line of code that is committed. AI should not be used for "responsibility washing." However, Copilot is a tool, and workers need their tools to be reliable. A carpenter doesn't have to

2019ncovmemory

'''
Usage: python archive_articles.py test.csv
Input: test.csv
name	url
   1	url1
   2	url2
   .....
output:
1.png
2.png

williballenthin

//------------------------------------------------
//--- 010 Editor v8.0.1 Binary Template
//
//      File: Transactional Registry Transaction Logs (.TxR)
//   Authors: Willi Ballenthin <[email protected]>
//   Version: 0.1
// Reference: https://www.fireeye.com/blog/threat-research/2019/01/digging-up-the-past-windows-registry-forensics-revisited.html
//------------------------------------------------

LittleEndian();

LoadLow

This is based on https://hugeh0ge.github.io/2019/11/04/Getting-Arbitrary-Code-Execution-from-fopen-s-2nd-Argument/

Credits: @hugeh0ge

It uses iconv, in php, in order to execute the same payload.

Uses cases :

• You control the first parameter of iconv (in_charset), you can set an env var and you can upload arbitrary files (.so library file and the gconv-modules file) and you know their path.
• You have a php RCE but system, shell_exec, curl_exec and other functions are disabled but you can setenv (and LD_PRELOAD is blacklisted).