Rick Mark

Dynamic Library Hardening - Read Only Thunks

Problem Today, late binding makes use of “thunks” to bind a call site to its eventual import.  These regions are setup as initialized mutable memory, meaning an errant instruction stream may be able to over write the function pointers arbitrarily.  Alternatives include static linking (infeasible due to size and update

Ubiquity UniFi Security and Boot-chain Analysis

This Paper Under Revision Due to further analysis, it seems that swapping the secure boot chain for alpine v2 devices early in the boot process via a device tree overlay is possible.  Therefore, this analysis may be based on a malware stack running on a device rather than UniFi’s

Google: From the Citadel to the Dauntless

DANGER: Incomplete analysis and conjecture based on real world observation. tl;dr Google’s Titan-M (codename citadel) is based on the prior generation of designs for the Chromebook EC (embeddedcontroller - Haven) which mediates the secure boot process.  While Google referrers to regions of the flash known as RO_Aand

Using the T2 for Detection and Forensics

Todays Need With the advent of modern security hardware, it has become near impossible to perform comprehensive security auditing of devices used in the field.  This has allowed malware to run at layers of the stack not accessible to traditional endpoint security.  Recent un-patchable hardware vulnerabilities that may have served

USB Security in the Linux Kernel

Dropbox not only works to ensure that our product is worthy of trust, but we look up and down the entire stack of components for risk and areas of improvement.  Like many companies, we employ Linux servers to power the Dropbox product.  We perform regular patching, secure configuration and performance

Work-in-Progress: Using Apple internal builds for RootKits

Backstory Found this years ago while being stalked in SF mojo_thor.  Recently I've found more kernel extensions beyond just MojoKDP that are involved.  MojoKDP was originally found by running a VM, then capturing the memory state providing a core dump. (see other repo) Overall Theory Two Possibilities:

The Security Weakness of the M1

tl;dr The M1 and iBoot was overall a massive step forward in boot integrity for our devices, but the use of an encrypted boot-loader (as opposed to EFI which was not encrypted) makes it’s security guarantees impossible to verify.  In addition, other regressions are outlined. Static and Dynamic

Dissection of the Apple Internet Recovery protocol and Security Analysis

NOTE: The authors' machine always downgrades from 10.15.3 to 10.13.0 via internet recovery, therefore some experiments may not be working the same due to a network issue with an attacker at a position of privilege on the network. Verification of BaseSystem.dmg and OSDInstall.dmg

Qualcomm Baseband Research

bbfw Zip package containing: * sbl1.mbn - Secondary Bootloader (after ROM PBL) * Info.plist - Apple update information * Options.plist - Zero? Seems in error? (Even empty plists have length) * qdsp6sw.mbn - Qualcomm Hexagon Digital Signal Processor (non-ARM core) * tz.mbn - Qualcomm TrustZone Implementation - QSEE * hyp.mbn

Plug'nPwn - Connect to Jailbreak

Authors * Rick Mark * mrarm * Aun-Ali Zaidi * h0m3us3r published: Oct 12, 2020 Plug'nPwn - Connect to Jailbreak State of the World: checkm8, checkra1n and the T2 For those just joining us, news broke last week about the jailbreaking of Apple’s T2 security processor in recent Macs. If you

ACE Controller Secrets

NOTE: This was originally published on blog.t8012.dev in conjunction with h0meus3r, mrarm, and aunali1 Introduction After our team successfully ported the checkm8 exploit to the AppleSilicon T2 chip, we began exploring methods for closed-case hardware debugging, or CCD, as found on other iDevices. On such devices, the Serial

Security Critical Kernel Object Confidentiality and Integrity

License This work is licensed under a Creative Commons Attribution 4.0 International License. From the Author Furthermore I make no intellectual property claims, other then attribution of work.  Therefore, from myself it can be used for both research as well as commercial works.  This paper draws on the ARM

Design: Hybrid PROM / SPI Flash

Todays Problem: Nearly every device makes use of SPI flash for early load boot-loader as well as recovery environments.  These devices are Non-Volatile storage areas that provide the foundation of security in modern computing.  Due to a rash of boot-kits, many manufacturers now make use of PKI based verification of

How Minimalism Hurts Security

Apple Device Boot Process Apple has for many years valued ease of use and consumer friendliness over actual security.  This is totally clear when you consider that an Apple laptop can have its security features disabled without any clear visual indicator of this lowered security state.  (Android and Chromebooks place

How Apple Gets Security Wrong

NOTE: Much of this is older analysis and some is addressed by Developer Mode and Lockdown mode in iOS 16 * Undocumented protocols (USB-PD, lightning, UTDM, usbmux, IPSW, etc) * Use of MFi to prevent research and disclosure * Lack of Physical Attestation for privileged operations * Hold a key to enable auto-DFU * DFU

Design: Surface Area Reduction of the CS/ME by Using Bogus Public Keys

The CS/ME is Scary… Because the CS/ME is run before the CPU comes up, and it has complete access to a system and is even designed for remote management (see Intel AMT) perhaps our classic approach isn’t working.  Classic “High Assurance” of the Intel ME has centered

DataMigration iOS Mitigations

Introduction While iOS continues to advance security controls on code with signing and entitlements, key aspects of the OS are lacking in security hardening.  This paper proposes two features that could be included in iOS to increase the security of subsystems that handle untrusted data and uses the DataMigration framework

The SIM Swap Revisited

Terms IMSI - The identifier for a particular line of service on the cellular network.  Fixed for the lifetime of the line (pending some unknown rotation scheme) IMEI - A unique device on the GSM network.  iPhones contain two IMEIs so that they can participate in Dual SIM (today DSS

Intel Goa’uld

About the name… Look… Lots of Stargate SG1 was playing while I slept, waking up to realize why the Intel ME layout was like it was (twocopies of the Boot partition sharing pages making it impossible for it to be for reasons of resiliency).  Because it includes an Intel AMT/

Apple USB Target Disk Mode

Introduction In earlier generations of Apple MacBook computers, TDM or Target Disk Mode was a boot mode that made all internal drives appear to an external FireWire capable system to be LUNs which could be consumed by another endpoint (Thisusually included the internal Hard Drive and CD/DVD-ROMs).  Because of

Abusing EFI Variables and the AMT

Speculation on How EFI was Modified: By simply having Ring 0 (kernel mode) one can place EFI variables into NVRAM via EFI runtime services.  If one of these variables is scanned as a valid FFV, that gives execute at level of Ring -1, from there modifying the SPI contents of

How To: Bypass T-Mobile SIM block, steal all their money, and leave no trace…

Disclaimer This is a tutorial to do something illegal to demonstrate how bad the vendor is, despite multiple complaints from me.  If you do this, you will likely be caught and go to prison.  I do not condone these actions and the experiments that prove their validity took place against

On Warren’s Plan to Break Up Facebook

The Difficulty with Ubiquious Services The reason that the utility of Facebook is what it is, is primarily its de-facto status as the ubiquitous system of record.  Before Facebook conversations in real life were a binary search tree of what system’s you shared in common (IRC, AIM, ICQ, LinkedIn,

How To: Bypass T-Mobile SIM block, steal all their money, and leave no trace…

Disclaimer ​​This is a tutorial to do something illegal to demonstrate how bad the vendor is, despite multiple complaints from me.  If you do this, you will likely be caught and go to prison.  I do not condone these actions and the experiments that prove their validity took place against

Puppeteer with ChromeOS

“Headed” Chrome Testing Recently I’ve been working on using Chrome and WebUSB to communicate with Apple iPhone/iPads which implement the usbmuxd protocol.  As I was working with this, developer ergonomics and testing became very important, and unlike a regular website “headless” testing was infeasible because of the reliance