Project Zero researcher found unpatched Android zero-day likely exploited by NSO group
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2019-2215 | Use-After-Free Privilege Escalation in Android Kernel (CVE-2019-2215) CVE-2019-2215 is a use-after-free flaw (CWE-416) in the Android kernel's binder.c IPC driver that allows privilege escalation from an application to the Linux kernel. Exploitation requires no user interaction, but an attacker must either run a malicious local application or chain the bug with a vulnerability in a network-facing application. Successful exploitation yields kernel-level code execution, effectively rooting the device and giving the attacker full control over apps, data, and communications. Affected parties include Android devices with unpatched kernels (reporting at the time indicated most Android phones were affected), plus products shipping affected Android kernel code, including Google Android, Debian/Ubuntu builds, and NetApp and Huawei offerings. The flaw was publicly disclosed and patched in Android's October 2019 security updates, public proof-of-concept exploits exist, and it is listed in CISA's Known Exploited Vulnerabilities catalog with a high (72.1%) EPSS probability of exploitation; headlines confirm in-the-wild use, including a Google Play app that leveraged it to deliver spyware. Do: Apply vendor-supplied updates per CISA's required action — for phones and tablets, ensure the device is on the October 2019 Android security patch level or later (check Settings > About phone > Android security patch level) and patch via MDM across your fleet; NetApp, Huawei, Debian, and Ubuntu customers should install their vendors' corresponding kernel updates. Because this is a local privilege escalation with no user interaction required, also patch any network-facing applications that could be chained with it, and hunt for signs of exploitation such as unexpected root or unknown sideloaded/rooting apps on managed devices. | 7.8 | 72% | KEV PoC ×2 |
| massbillions of devices |
Full article617 words · extracted from securityaffairs.com · click to collapse
Google Project Zero researcher Maddie Stone discovered a critical unpatched zero-day vulnerability affecting the Android mobile operating system.
Maddie Stone, a member of the Google elite team Project Zero, discovered a critical unpatched zero-day vulnerability affecting the Android mobile operating system. According to the expert, the bug, tracked as CVE-2019-2215, was allegedly being used or sold by the controversial surveillance firm NSO Group.
Maddie Stone published technical details and a proof-of-concept exploit for the high-severity security vulnerability, seven days after she reported it to the colleagues of the Android security team.
https://twitter.com/maddiestone/status/1179918644089774081
The flaw is a use-after-free vulnerability that affects the Android kernel’s binder driver, it could be exploited by a local privileged attacker or a malicious app to escalate privileges to gain root access to a vulnerable device. Experts warn it could potentially allow to fully compromise the device.
“There is a use-after-free of the wait member in the binder_thread struct in the binder driver at /drivers/android/binder.c.” reads the security advisory.
“As described in the upstream commit: “binder_poll() passes the thread->wait waitqueue that can be slept on for work. When a thread that uses
epoll explicitly exits using BINDER_THREAD_EXIT, the waitqueue is freed, but it is never removed from the corresponding epoll data structure. When
the process subsequently exits, the epoll cleanup code tries to access the waitlist, which results in a use-after-free.”
The flaw affects versions of Android kernel released before April last year. This vulnerability was addressed in Dec 2017 in the 4.14 LTS kernel [1], AOSP android 3.18 kernel [2], AOSP android 4.4 kernel [3], and AOSP android 4.9 kernel [4]. The expert pointed out that Pixel 2 with most recent security bulletin is still vulnerable based on source code review.
This means that most of the Android devices available on the market with the unpatched kernel are still vulnerable to this vulnerability, even is the owners have installed the latest Android security updates.
Some of the devices which appear to be vulnerable based on source code review are:
1) Pixel 2 with Android 9 and Android 10 preview (https://android.googlesource.com/kernel/msm/+/refs/heads/android-msm-wahoo-4.4-q-preview-6/)
2) Huawei P20
3) Xiaomi Redmi 5A
4) Xiaomi Redmi Note 5
5) Xiaomi A1
6) A3
7) Moto Z3
8) Oreo LG phones (run according to )
9) Samsung S7, S8, S9
Maddie Stone explained that the flaw is accessible from inside the Chrome sandbox, the issue is exploitable in Chrome’s renderer processes under Android’s ‘isolated_app’ SELinux domain. This means that a remote attacker could potentially exploit the flaw by chaining it with a Chrome rendering issue.
“The bug is a local privilege escalation vulnerability that allows for a full compromise of a vulnerable device. If the exploit is delivered via the web, it only needs to be paired with a renderer exploit, as this vulnerability is accessible through the sandbox.” Stone said.
“I’ve attached a local exploit proof-of-concept to demonstrate how this bug can be used to gain arbitrary kernel read/write when run locally. It only requires untrusted app code execution to exploit CVE-2019-2215.”
Google is expected to release a security patch for its October’s Android Security Bulletin.
“This issue is rated as High severity on Android and by itself requires installation of a malicious application for potential exploitation. Any other vectors, such as via web browser, require chaining with an additional exploit,” concludes the Chromium blog. “We have notified Android partners, and the patch is available on the Android Common Kernel. Pixel 3 and 3a devices are not vulnerable while Pixel 1 and 2 devices will be receiving updates for this issue as part of the October update.”
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Text extracted automatically; images, tables and formatting may be missing. Original: https://securityaffairs.com/92124/hacking/android-kernel-zero-day.html