Windows Kernel Logic Bug Class: Access Mode Mismatch in IO Manager

Posted by James Forshaw, Project Zero This blog post is an in-depth look at an interesting logic bug class in the Windows Kernel and what I did to try to get it fixed with our partners at Microsoft. The maximum impact of the bug class is local privilege escalation if kernel and driver developers...

Hack The Galaxy: Hunting Bugs in the Samsung Galaxy S6 Edge

Posted by Natalie Silvanovich, Planner of Bug Bashes Recently, Project Zero researched a popular Android phone, the Samsung Galaxy S6 Edge. We discovered and reported 11 high-impact security issues as a result. This post discusses our motivations behind the research, our approach in looking for...

Enabling QR codes in Internet Explorer, or a story of a cross-platform memory disclosure

Posted by Mateusz Jurczyk of Google Project Zero In the previous series of posts parts 1 2 3 4, we discussed the exploitation process of a serious “blend” vulnerability CVE-2015-0093 / CVE-2015-3052, which was special in that it provided the attacker with an extremely powerful primitive arbitrary...

An analysis of an in-the-wild iOS Safari WebContent to GPU Process exploit

By Ian Beer A graph representation of the sandbox escape NSExpression payload In April this year Google's Threat Analysis Group, in collaboration with Amnesty International, discovered an in-the-wild iPhone zero-day exploit chain being used in targeted attacks delivered via malicious link. The...

JITSploitation III: Subverting Control Flow

Posted by Samuel Groß, Project Zero This three-part series highlights the technical challenges involved in finding and exploiting JavaScript engine vulnerabilities in modern web browsers and evaluates current exploit mitigation technologies. The exploited vulnerability, CVE-2020-9802, was fixed i...

The Windows Registry Adventure #6: Kernel-mode objects

Posted by Mateusz Jurczyk, Google Project Zero Welcome back to the Windows Registry Adventure! In the previous installment of the series, we took a deep look into the internals of the regf hive format. Understanding this foundational aspect of the registry is crucial, as it illuminates the design...

SockPuppet: A Walkthrough of a Kernel Exploit for iOS 12.4

Posted by Ned Williamson, 20% on Project Zero Introduction I have a somewhat unique opportunity in this writeup to highlight my experience as an iOS research newcomer. Many high quality iOS kernel exploitation writeups have been published, but those often feature weaker initial primitives combine...

Bypassing VirtualBox Process Hardening on Windows

Posted by James Forshaw, Project Zero Processes on Windows are securable objects, which prevents one user logged into a Windows machine from compromising another user’s processes. This is a pretty important security feature, at least from the perspective of a non-administrator user. The security...

Exploiting the DRAM rowhammer bug to gain kernel privileges

Rowhammer blog post draft Posted by Mark Seaborn, sandbox builder and breaker, with contributions by Thomas Dullien, reverse engineer This guest post continues Project Zero’s practice of promoting excellence in security research on the Project Zero blog Overview “Rowhammer” is a problem with some...

Taking a page from the kernel's book: A TLB issue in mremap()

Posted by Jann Horn, Project Zero This is a technical blog post about TLB flushing bugs in kernels, intended for people interested in kernel security and memory management. Introduction: Bugs in Memory Management code There have been some pretty scary bugs in memory management in the past, like:...

This shouldn't have happened: A vulnerability postmortem

Posted by Tavis Ormandy, Project Zero Introduction This is an unusual blog post. I normally write posts to highlight some hidden attack surface or interesting complex vulnerability class. This time, I want to talk about a vulnerability that is neither of those things. The striking thing about thi...

Understanding Network Access in Windows AppContainers

Posted by James Forshaw, Project Zero Recently I've been delving into the inner workings of the Windows Firewall. This is interesting to me as it's used to enforce various restrictions such as whether AppContainer sandboxed applications can access the network. Being able to bypass network...

Injecting Code into Windows Protected Processes using COM - Part 1

Posted by James Forshaw, Google Project Zero At Recon Montreal 2018 I presented “Unknown Known DLLs and other Code Integrity Trust Violations” with Alex Ionescu. We described the implementation of Microsoft Windows’ Code Integrity mechanisms and how Microsoft implemented Protected Processes PP. A...

Using Binary Diffing to Discover Windows Kernel Memory Disclosure Bugs

Posted by Mateusz Jurczyk of Google Project Zero Patch diffing is a common technique of comparing two binary builds of the same code – a known-vulnerable one and one containing a security fix. It is often used to determine the technical details behind ambiguously-worded bulletins, and to establis...

The quantum state of Linux kernel garbage collection CVE-2021-0920 (Part I)

A deep dive into an in-the-wild Android exploit Guest Post by Xingyu Jin, Android Security Research This is part one of a two-part guest blog post, where first we'll look at the root cause of the CVE-2021-0920 vulnerability. In the second post, we'll dive into the in-the-wild 0-day exploitation o...

Fuzzing ImageIO

Posted by Samuel Groß, Project Zero This blog post discusses an old type of issue, vulnerabilities in image format parsers, in a newer context: on interactionless code paths in popular messenger apps. This research was focused on the Apple ecosystem and the image parsing API provided by it: the...

An Autopsy on a Zombie In-the-Wild 0-day

Posted by Maddie Stone, Google Project Zero Whenever there’s a new in-the-wild 0-day disclosed, I’m very interested in understanding the root cause of the bug. This allows us to then understand if it was fully fixed, look for variants, and brainstorm new mitigations. This blog is the story of a...

Mind the Gap

By Ian Beer, Project Zero Note: The vulnerabilities discussed in this blog post CVE-2022-33917 are fixed by the upstream vendor, but at the time of publication, these fixes have not yet made it downstream to affected Android devices including Pixel, Samsung, Xiaomi, Oppo and others. Devices with ...

Zooming in on Zero-click Exploits

Posted by Natalie Silvanovich, Project Zero Zoom is a video conferencing platform that has gained popularity throughout the pandemic. Unlike other video conferencing systems that I have investigated, where one user initiates a call that other users must immediately accept or reject, Zoom calls ar...

JITSploitation I: A JIT Bug

By Samuel Groß, Project Zero This three-part series highlights the technical challenges involved in finding and exploiting JavaScript engine vulnerabilities in modern web browsers and evaluates current exploit mitigation technologies. The exploited vulnerability, CVE-2020-9802, was fixed in iOS...

A Shadow of our Former Self

Posted by James Forshaw of Google Project Zero “Necessity is the Mother of Invention” as it’s said, and this is no more true than when looking for and exploiting security vulnerabilities. When new exploit mitigations are introduced, either a way of bypassing the mitigation is needed or an...

A Look at iMessage in iOS 14

Posted By Samuel Groß, Project Zero On December 20, Citizenlab published “The Great iPwn”, detailing how “Journalists were Hacked with Suspected NSO Group iMessage ‘Zero-Click’ Exploit”. Of particular interest is the following note: “We do not believe that the exploit works against iOS 14 and...

pwn4fun Spring 2014 - Safari - Part II

Posted by Ian Beer TL;DR An OS X GPU driver trusted a user-supplied kernel C++ object pointer and called a virtual function. The IOKit registry contained kernel pointers which were used defeat kASLR. A kernel ROP payload ran Calculator.app as root using a convenient kernel API. Overview of part I...

Driving forward in Android drivers

Posted by Seth Jenkins, Google Project Zero Introduction Android's open-source ecosystem has led to an incredible diversity of manufacturers and vendors developing software that runs on a broad variety of hardware. This hardware requires supporting drivers, meaning that many different codebases...

CVE-2021-1782, an iOS in-the-wild vulnerability in vouchers

Posted by Ian Beer, Google Project Zero This blog post is my analysis of a vulnerability exploited in the wild and patched in early 2021. Like the writeup published last week looking at an ASN.1 parser bug, this blog post is based on the notes I took as I was analyzing the patch and trying to...

Remote iPhone Exploitation Part 2: Bringing Light into the Darkness -- a Remote ASLR Bypass

Posted by Samuel Groß, Project Zero This post is the second in a series about a remote, interactionless iPhone exploit over iMessage.The first blog post, which introduced the exploited vulnerability, can be found here. The initial primitive gained from the vulnerability is an absolute address...

FORCEDENTRY: Sandbox Escape

Posted by Ian Beer & Samuel Groß of Google Project Zero We want to thank Citizen Lab for sharing a sample of the FORCEDENTRY exploit with us, and Apple’s Security Engineering and Architecture SEAR group for collaborating with us on the technical analysis. Any editorial opinions reflected below ar...

MMS Exploit Part 1: Introduction to the Samsung Qmage Codec and Remote Attack Surface

Posted by Mateusz Jurczyk, Project Zero This post is the first of a multi-part series capturing my journey from discovering a vulnerable little-known Samsung image codec, to completing a remote zero-click MMS attack that worked on the latest Samsung flagship devices. New posts will be published a...

Windows 10^H^H Symbolic Link Mitigations

Posted by James Forshaw, abusing symbolic links like it’s 1999. For the past couple of years I’ve been researching Windows elevation of privilege attacks. This might be escaping sandboxing or gaining system privileges. One of the techniques I’ve used multiple times is abusing the symbolic link...

Attacking the Qualcomm Adreno GPU

Posted by Ben Hawkes, Project Zero When writing an Android exploit, breaking out of the application sandbox is often a key step. There are a wide range of remote attacks that give you code execution with the privileges of an application like the browser or a messaging application, but a sandbox...

Windows Bug Class: Accessing Trapped COM Objects with IDispatch

Posted by James Forshaw, Google Project Zero Object orientated remoting technologies such as DCOM and .NET Remoting make it very easy to develop an object-orientated interface to a service which can cross process and security boundaries. This is because they're designed to support a wide range of...

A survey of recent iOS kernel exploits

Posted by Brandon Azad, Project Zero I recently found myself wishing for a single online reference providing a brief summary of the high-level exploit flow of every public iOS kernel exploit in recent years; since no such document existed, I decided to create it here. This post summarizes origina...

Virtually Unlimited Memory: Escaping the Chrome Sandbox

Posted by Mark Brand, Exploit Technique Archaeologist. Introduction After discovering a collection of possible sandbox escape vulnerabilities in Chrome, it seemed worthwhile to exploit one of these issues as a full-chain exploit together with a renderer vulnerability to get a better understanding...

You Won't Believe what this One Line Change Did to the Chrome Sandbox

Posted by James Forshaw, Project Zero The Chromium sandbox on Windows has stood the test of time. It’s considered one of the better sandboxing mechanisms deployed at scale without requiring elevated privileges to function. For all the good, it does have its weaknesses. The main one being the...

A 0-click exploit chain for the Pixel 10: When a Door Closes, a Window Opens

Posted by Seth Jenkins We recently published an exploit chain for the Google Pixel 9 that demonstrated it was possible to go from a zero-click context to root on Android in just two exploits. The Dolby 0-click vulnerability existed across all of Android, until it was patched in January 2026. Whil...

Remote iPhone Exploitation Part 1: Poking Memory via iMessage and CVE-2019-8641

Posted by Samuel Groß, Project Zero Introduction This is the first blog post in a three-part series that will detail how a vulnerability in iMessage can be exploited remotely without any user interaction on iOS 12.4 fixed in iOS 12.4.1 in August 2019. It is essentially a more detailed version of ...

In-the-wild iOS Exploit Chain 4

Posted by Ian Beer, Project Zero TL;DR This exploit chain supported iOS 12-12.1, although the two vulnerabilities were unpatched when we discovered the chain in the wild. It was these two vulnerabilities which we reported to Apple with a 7-day deadline, leading to the release of iOS 12.1.4. The...

Attacking ECMAScript Engines with Redefinition

Posted by Natalie Silvanovich = function return n; ECMAScript has a property where almost all functions and variables can be dynamically redefined. This can lead to vulnerabilities in situations where native code assumes a function or variable behaves a certain way when accessed or does not have...

FF Sandbox Escape (CVE-2020-12388)

By James Forshaw, Project Zero In my previous blog post I discussed an issue with the Windows Kernel’s handling of Restricted Tokens which allowed me to escape the Chrome GPU sandbox. Originally I’d planned to use Firefox for the proof-of-concept as Firefox uses the same effective sandbox level a...

Exploiting CVE-2022-42703 - Bringing back the stack attack

Seth Jenkins, Project Zero This blog post details an exploit for CVE-2022-42703 P0 issue 2351 - Fixed 5 September 2022, a bug Jann Horn found in the Linux kernel's memory management MM subsystem that leads to a use-after-free on struct anonvma. As the bug is very complex I certainly struggle to...

Windows‌ ‌Exploitation‌ ‌Tricks:‌ ‌Spoofing‌ ‌Named‌ ‌Pipe‌ ‌Client‌ ‌PID‌

Posted by James Forshaw, Project Zero While researching the Access Mode Mismatch in IO Manager bug class I came across an interesting feature in named pipes which allows a server to query the connected clients PID. This feature was introduced in Vista and is exposed to servers through the...

A year of Windows kernel font fuzzing #1: the results

Posted by Mateusz Jurczyk of Google Project Zero This post series is about how we used at-scale fuzzing to discover and report a total of 16 vulnerabilities in the handling of TrueType and OpenType fonts in the Windows kernel during the last year. In part 1 here, we present a general overview of...

Windows Tooling Updates: OleView.NET

Posted by James Forshaw, Google Project Zero This is a short blog post about some recent improvements I've been making to the OleView.NET tool which has been released as part of version 1.16. The tool is designed to discover the attack surface of Windows COM and find security vulnerabilities such...

Adventures in Video Conferencing Part 2: Fun with FaceTime

Posted by Natalie Silvanovich, Project Zero FaceTime is Apple’s video conferencing application for iOS and Mac. It is closed source, and does not appear to use any third-party libraries for its core functionality. I wondered whether fuzzing the contents of FaceTime’s audio and video streams would...

Over The Air - Vol. 2, Pt. 2: Exploiting The Wi-Fi Stack on Apple Devices

Posted by Gal Beniamini, Project Zero In this blog post we’ll continue our journey towards over-the-air exploitation of the iPhone, by means of Wi-Fi communication alone. This part of the research will focus on the firmware running on Broadcom’s Wi-Fi SoC present on the iPhone 7. We’ll begin by...

Over The Air: Exploiting Broadcom’s Wi-Fi Stack (Part 1)

Posted by Gal Beniamini, Project Zero It’s a well understood fact that platform security is an integral part of the security of complex systems. For mobile devices, this statement rings even truer; modern mobile platforms include multiple processing units, all elaborately communicating with one...

The Windows Registry Adventure #3: Learning resources

Posted by Mateusz Jurczyk, Google Project Zero When tackling a new vulnerability research target, especially a closed-source one, I prioritize gathering as much information about it as possible. This gets especially interesting when it's a subsystem as old and fundamental as the Windows registry...

DER Entitlements: The (Brief) Return of the Psychic Paper

Posted by Ivan Fratric, Project Zero Note: The vulnerability discussed here, CVE-2022-42855, was fixed in iOS 15.7.2 and macOS Monterey 12.6.2. While the vulnerability did not appear to be exploitable on iOS 16 and macOS Ventura, iOS 16.2 and macOS Ventura 13.1 nevertheless shipped hardening...

A Token’s Tale

Posted by James Forshaw currently impersonating NT AUTHORITY\SYSTEM. Much as I enjoy the process of vulnerability research sometimes there’s a significant disparity between the difficulty of finding a vulnerability and exploiting it. The Project Zero blog contains numerous examples of complex...

The Windows Registry Adventure #2: A brief history of the feature

Posted by Mateusz Jurczyk, Google Project Zero Before diving into the low-level security aspects of the registry, it is important to understand its role in the operating system and a bit of history behind it. In essence, the registry is a hierarchical database made of named "keys" and "values",...