Google has released the November 2021 Android Security Bulletin, giving carriers and device makers a fresh set of patches to install. Though Google puts out the Android security patches each month, the job of actually getting the fixes to end users falls on the telcos and/or device manufacturers themselves. Those partners vary in their ability to release the patches in a timely fashion.
The Android Security Bulletin contains details of security vulnerabilities affecting Android devices. Security patch levels of 06-11-2021 or later address all of these issues.
The most severe of these issues is a critical security vulnerability in the System component that could enable a remote attacker using a specially crafted transmission to execute arbitrary code within the context of a privileged process. The severity assessment is based on the effect that exploiting the vulnerability would possibly have on an affected device, assuming the platform and service mitigations are turned off for development purposes or if successfully bypassed.
Alongside the bulletin, Google have released a security update to Google devices through an over-the-air (OTA) update. The Google device firmware images have also been released to the Google Developer site. Security patch levels of November 5, 2021 or later address all of these issues.
The tables below contains a list of security vulnerabilities, the Common Vulnerability and Exposures ID (CVE), the assessed severity, and whether or not Google devices are affected. The severity assessment is based on the effect that exploiting the vulnerability would possibly have on an affected device, assuming the platform and service mitigations are disabled for development purposes or if successfully bypassed.
Android and Google Service Mitigation’s
This is a summary of the mitigation’s provided by the Android security platform and service protections such as Google Play Protect. These capabilities reduce the likelihood that security vulnerabilities could be successfully exploited on Android.
- Exploitation for many issues on Android is made more difficult by enhancements in newer versions of the Android platform. All users are encouraged to update to the latest version of Android where possible.
- The Android security team actively monitors for abuse through Google Play Protect and warns users about Potentially Harmful Applications. Google Play Protect is enabled by default on devices with Google Mobile Services, and is especially important for users who install apps from outside of Google Play.
Terminology
You will find different types of vulnerabilities listed. Possible types include:
- RCE – Remote code execution
- EoP – Elevation of privilege
- ID – Information disclosure
- DoS – Denial of service
- N/A – Classification not available
01-11-2021 security patch level—Vulnerability details
Framework
The most severe vulnerability in this section could enable a local attacker to gain access to additional permissions with no user interaction required.
| CVE | References | Type | Severity | Updated AOSP versions |
|---|---|---|---|---|
| CVE-2021-0799 | A-197647956 | EoP | High | 12 |
| CVE-2021-0921 | A-195962697 | EoP | High | 11 |
| CVE-2021-0923 | A-195338390 | EoP | High | 12 |
| CVE-2021-0926 | A-191053931 | EoP | High | 9, 10, 11, 12 |
| CVE-2021-0933 | A-172251622 | EoP | High | 9, 10, 11, 12 |
| CVE-2020-13871 | A-192606047 | ID | High | 11 |
| CVE-2021-0653 | A-177931370 | ID | High | 9, 10, 11 |
| CVE-2021-0922 | A-195630721 | EoP | Moderate | 11 |
Media Framework
The most severe vulnerability in this section could enable a local malicious application to bypass user interaction requirements in order to gain access to additional permissions.
| CVE | References | Type | Severity | Updated AOSP versions |
|---|---|---|---|---|
| CVE-2021-0928 | A-188675581 | EoP | High | 9, 10, 11 |
| CVE-2021-0650 | A-190286685 | ID | High | 9, 10, 11 |
System
The most severe vulnerability in this section could enable a remote attacker using a specially crafted transmission to execute arbitrary code within the context of a privileged process.
| CVE | References | Type | Severity | Updated AOSP versions |
|---|---|---|---|---|
| CVE-2021-0918 | A-197536150 | RCE | Critical | 12 |
| CVE-2021-0930 | A-181660091 | RCE | Critical | 9, 10, 11, 12 |
| CVE-2021-0434 | A-167403112 | EoP | High | 9, 10, 11 |
| CVE-2021-0649 | A-191382886 | EoP | High | 11 |
| CVE-2021-0932 | A-173025705 | EoP | High | 10 |
| CVE-2021-0925 | A-191444150 | ID | High | 12 |
| CVE-2021-0931 | A-180747689 | ID | High | 9, 10, 11, 12 |
| CVE-2021-0919 | A-197336441 | DoS | Moderate | 9, 10, 11 |
Google Play system updates
The following issues are included in Project Mainline components.
| Component | CVE |
|---|---|
| Tethering | CVE-2021-0653 |
| Media Framework components | CVE-2021-0650 |
| Tethering | CVE-2021-0649 |
05-11-2021 security patch level—Vulnerability details
Kernel components
The most severe vulnerability in this section could result in local escalation of privilege due to a use after free.
| CVE | References | Type | Severity | Component |
|---|---|---|---|---|
| CVE-2021-0920 | A-196926917 Upstream kernel | EoP | High | Kernel |
| CVE-2021-0924 | A-194461020 Upstream kernel | EoP | High | USB |
| CVE-2021-0929 | A-187527909 Upstream kernel | EoP | High | ION |
Android TV
The most severe vulnerability in this section could enable a proximate attacker to silently pair with a TV and execute arbitrary code with no privileges or user interaction required.
| CVE | References | Type | Severity | Component |
|---|---|---|---|---|
| CVE-2021-0889 | RCE | Critical | Android TV Remote Service | |
| CVE-2021-0927 | EoP | High | TvInputManager |
MediaTek components
This vulnerability affects MediaTek components and further details are available directly from MediaTek. The severity assessment of this issue is provided directly by MediaTek.
| CVE | References | Severity | Component |
|---|---|---|---|
| CVE-2021-0672 | A-199678035 M-ALPS05969704 | High | Browser app |
Qualcomm closed-source components
These vulnerabilities affect Qualcomm closed-source components and are described in further detail in the appropriate Qualcomm security bulletin or security alert. The severity assessment of these issues is provided directly by Qualcomm.
| CVE | References | Severity | Component |
|---|---|---|---|
| CVE-2021-1924 | A-187074639 | Critical | Closed-source component |
| CVE-2021-1975 | A-187074053 | Critical | Closed-source component |
| CVE-2021-1921 | A-187074562 | High | Closed-source component |
| CVE-2021-1973 | A-187074563 | High | Closed-source component |
| CVE-2021-1979 | A-187073200 | High | Closed-source component |
| CVE-2021-1981 | A-187074764 | High | Closed-source component |
| CVE-2021-1982 | A-187074484 | High | Closed-source component |
| CVE-2021-30254 | A-187074014 | High | Closed-source component |
| CVE-2021-30255 | A-187074054 | High | Closed-source component |
| CVE-2021-30259 | A-187074564 | High | Closed-source component |
| CVE-2021-30284 | A-187074013 | High | Closed-source component |
06-11-2021 security patch level vulnerability details
Kernel components
The vulnerability in this section could lead to a local escalation of privilege due to a use after free.
| CVE | References | Type | Severity | Component |
|---|---|---|---|---|
| CVE-2021-1048 | A-204573007 Upstream kernel | EoP | High | Kernel |
Full details of the November 2021 Android Security Bulletin are available here.
