CVE-2019-1010221 in LineageOS
Summary
by MITRE
LineageOS 16.0 and earlier is affected by: Incorrect Access Control. The impact is: The property checked by `adb root` can also be set in a normal adb shell session. The component is: adb shell (patches to fix this are at https://review.lineageos.org/c/LineageOS/android_system_core/+/234800, https://review.lineageos.org/c/LineageOS/android_device_lineage_sepolicy/+/234799). The attack vector is: When adb is enabled, and an attacker has physical access, `adb shell setprop service.adb.root 1` allows restarting adb as root.
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Analysis
by VulDB Data Team • 11/06/2023
This vulnerability resides in LineageOS 16.0 and earlier versions, specifically within the Android Debug Bridge (adb) implementation where an incorrect access control flaw exists. The vulnerability stems from the improper handling of the service.adb.root property which should normally be restricted to privileged operations but can be manipulated by regular adb shell sessions. The technical flaw manifests when an attacker with physical access to a device running vulnerable LineageOS can execute the command `adb shell setprop service.adb.root 1` to elevate their privileges, effectively bypassing the intended security controls that should only allow root access through the proper `adb root` command execution. This represents a classic privilege escalation vulnerability where the system's access control mechanisms fail to properly enforce the distinction between normal user sessions and privileged operations, allowing unauthorized elevation of privileges through property manipulation.
The operational impact of this vulnerability is significant for devices with adb enabled, particularly in environments where physical access cannot be guaranteed. When an attacker gains physical access to a vulnerable device, they can exploit this weakness to gain root-level access without requiring additional authentication or specialized tools beyond having adb enabled. The attack vector is particularly concerning because it leverages the legitimate adb functionality that many users enable for development or debugging purposes, making the exploitation more隐蔽 and less likely to trigger security alerts. This vulnerability directly maps to CWE-284 Access Control Flaws, specifically targeting improper access control mechanisms that allow unauthorized privilege escalation. The attack requires only physical access and an existing adb session, making it particularly dangerous for mobile devices where physical security is often assumed to be sufficient.
The security implications extend beyond simple privilege escalation as this vulnerability can enable attackers to bypass device security controls entirely, potentially allowing for full system compromise including access to encrypted data, modification of system files, and installation of malicious software. The vulnerability affects the core adb shell functionality and demonstrates a critical failure in the SELinux security policies that should normally prevent such property modifications. This flaw represents a failure in the principle of least privilege where the system allows unrestricted access to critical system properties that should be protected from normal user sessions. Organizations and individuals using vulnerable LineageOS versions should immediately implement mitigations including disabling adb when not actively needed, ensuring proper physical security controls, and applying the available patches referenced in the LineageOS review system. The vulnerability also aligns with ATT&CK technique T1059.001 Command and Scripting Interpreter: PowerShell where adversaries may leverage system tools to execute privileged commands, though in this case the exploitation occurs through adb shell rather than PowerShell specifically. The patch implementations referenced in the LineageOS review system address this by strengthening the access controls around the service.adb.root property to prevent modification from normal shell sessions, ensuring that only properly authenticated root operations can modify this critical system property.