CVE-2019-2181 in Android
Summary
by MITRE
In binder_transaction of binder.c in the Android kernel, there is a possible out of bounds write due to an integer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation.
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Analysis
by VulDB Data Team • 08/10/2025
The vulnerability identified as CVE-2019-2181 resides within the Android kernel's binder driver implementation, specifically in the binder_transaction function located in binder.c. This flaw represents a critical security weakness that could enable local privilege escalation attacks. The vulnerability stems from an integer overflow condition that occurs during the processing of binder transactions, which are fundamental mechanisms used for inter-process communication within the Android operating system. The binder driver serves as the core component facilitating communication between different Android applications and system services, making this vulnerability particularly dangerous as it affects the foundational communication infrastructure.
The technical root cause of this vulnerability involves an integer overflow that leads to an out-of-bounds write condition. When processing certain binder transactions, the kernel fails to properly validate the size parameters of data structures being manipulated, allowing an attacker to craft malicious input that causes integer arithmetic to overflow. This overflow results in a buffer boundary being exceeded, enabling arbitrary memory writes that can be exploited to overwrite critical kernel data structures or function pointers. The vulnerability is classified under CWE-190 as an integer overflow condition, specifically manifesting as an out-of-bounds write that can be leveraged for privilege escalation. The attacker must have local access to the device and be able to execute code in the context of an unprivileged user, but no additional privileges are required beyond the initial access to exploit this weakness.
The operational impact of CVE-2019-2181 extends beyond simple privilege escalation as it represents a significant threat to Android device security and integrity. An attacker who successfully exploits this vulnerability can gain root-level privileges on the device, enabling complete control over all system resources, applications, and user data. This capability allows for persistent backdoor installation, data exfiltration, system monitoring, and the ability to evade detection mechanisms. The vulnerability affects all Android versions up to and including Android 9.0, making it particularly concerning given the widespread deployment of these systems. The exploitation requires user interaction, which means that social engineering or other attack vectors would be needed to initially gain execution privileges on the target device, but once achieved, the privilege escalation is automatic and reliable.
Mitigation strategies for CVE-2019-2181 should focus on immediate patch deployment and system hardening measures. Android security patches addressing this vulnerability were released as part of the Android Security Bulletin for September 2019, and users should immediately install the latest security updates from their device manufacturers. System administrators should implement monitoring for suspicious binder transaction activities and consider deploying kernel module integrity checking mechanisms. The vulnerability aligns with ATT&CK technique T1068 which covers "Exploitation for Privilege Escalation" and T1548.001 which covers "Abuse Elevation Control Mechanism". Organizations should also consider implementing additional security controls such as SELinux policy enforcement, kernel address space layout randomization, and runtime application protection measures to reduce the attack surface and prevent exploitation even if the vulnerability remains unpatched. Device manufacturers should ensure that their security update distribution mechanisms are functioning properly to deliver these critical patches to users in a timely manner.