Untethered initroot (USENIX WOOT ’17)
By Roee Hay (@roeehay)
August 30, 2017
In USENIX WOOT ‘17, that took place earlier this month in Vancouver, we presented our paper, “fastboot oem vuln: Android Bootloader Vulnerabilities in Vendor Customizations”, covering a year’s work in Android bootloaders research. Our paper also includes some previously undisclosed details on CVE-2016-10277, a critical kernel command-line injection vulnerability in the Motorola Android Bootloader (ABOOT) that we had found and blogged about. In the previous couple of blog posts, we demonstrated a tethered unrestricted root exploit against that vulnerability, that we later extended to other Moto devices – G4 & G5. Additional Moto devices have also been confirmed by the community. In the WOOT’17 paper we describe a natural continuation of that exploit – a second stage untethered secure boot & device locking bypass (tested to be working on the vulnerable versions of Nexus 6, Moto G4 & G5). Moreover, we also present in the paper and this blog post other second stage exploits, such as persistent kernel code execution in Nexus 6, the ability to downgrade critical partitions (such as the bootloaders chain and TrustZone), unlocking a re-locked Nexus 6 bootloader, and more. As usual, our PoC exploit is publicly available in our GitHub repo. DISCLAIMER: Unlike the previous ephemeral jailbreak, the one presented today may brick your device. For example, during the development of it, we had to unlock our (luckily unlockable!) Moto G5 device in order to unbrick it.[…]
fastboot oem vuln: Android Bootloader Vulnerabilities in Vendor Customizations:
We discuss the fastboot interface of the Android bootloader, an area of fragmentation in Android devices. We then present a variety of vulnerabilities we have found across multiple Android devices. Most notable ones include Secure Boot & Device Locking bypasses in the Motorola and OnePlus 3/3T bootloaders. Another critical flaw in OnePlus 3/3T enables easy attacks by malicious chargers – the only prerequisite is a powered-off device to be connected. An unexpected attack vector in Nexus 9 is also shown – malicious headphones. Other discovered weaknesses allow for data exfiltration (including a memory dumping of a Nexus 5X device), enablement of hidden functionality such as access to the device’s modem diagnostics and AT interfaces , and attacks against internal System-on-Chips (SoCs) found on the Nexus 9 board.
abootool: Simple fuzzer for discovering hidden fastboot gems. Modus Operandi: Based on static knowledge (strings fetched from available bootloader images), dynamically fuzz for hidden fastboot OEM commands.
Owning a Locked OnePlus 3/3T: Bootloader Vulnerabilities
Feb 08, 2017 • Roee Hay
In this blog post I disclose two vulnerabilities in the OnePlus 3/3T bootloader. The first one, CVE-2017-5626, is a critical severity vulnerability affecting OxygenOS 3.2-4.0.1 (4.0.2 is patched). The vulnerability allows for a physical adversary (or one with ADB/fastboot access) to bypass the bootloader’s lock state, even when Allow OEM Unlocking is disabled, without user confirmation and without triggering a factory reset. This vulnerability allows for kernel code execution (albeit with a 5 seconds warning upon boot). The second vulnerability, CVE-2017-5624, affecting all versions of OxygenOS to date (Feb 10 UPDATE: OxygenOS 4.0.3, released Feb 09, seems to be patched), allows the attacker to disable dm-verity. The combination of the vulnerabilities enables a powerful attack – persistent highly privileged code execution without any warning to the user and with access to the original user’s data (after the victim enters his credentials). Both issues were responsibly disclosed to and acknowledged by OnePlus Security. The first vulnerability, CVE-2017-5626, was reported on January 23rd. It was also found independently by a OnePlus engineer. CVE-2017-5624, reported on January 16th, should be fixed in a future OxygenOS release – the reason for its today’s public disclosure is because someone already published it on January 24th. Disclaimer: I tested the vulnerabilities on OnePlus 3 only, but OnePlus 3T contains the vulnerable code too.[…[
IBM’s SecurityIntelligence has a story on attacking Android’s Custom Boot Modes.
Android Vulnerabilities: Attacking Nexus 6 and 6P Custom Boot Modes
By Roee Hay
Co-authored by Michael Goberman.
In recent months, the X-Force Application Security Research Team has discovered several previously undisclosed Android vulnerabilities. The November 2016 and January 2017 Android Security Bulletins included patches to one high-severity vulnerability, CVE-2016-8467, in Nexus 6 and 6P. Our new paper, “Attacking Nexus 6 & 6P Custom Bootmodes,” discusses this vulnerability as well as CVE-2016-6678.[…]