CVE-2018-9409 in Android
Summary
by MITRE • 11/19/2024
In HWCSession::SetColorModeById of hwc_session.cpp, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 11/21/2024
The vulnerability identified as CVE-2018-9409 represents a critical security flaw within the hardware composer subsystem of Android operating systems. This issue resides in the HWCSession::SetColorModeById function located in the hwc_session.cpp source file, which forms part of the Android hardware abstraction layer responsible for managing display composition operations. The vulnerability stems from a fundamental lack of input validation that allows malicious actors to manipulate memory boundaries during color mode configuration operations.
The technical nature of this flaw classifies it as a buffer overflow vulnerability with specific characteristics that make it particularly dangerous for privilege escalation attacks. When the system processes color mode identifiers through the SetColorModeById function, it fails to validate the input parameters against predefined boundaries before writing data to memory locations. This missing bounds check creates a scenario where an attacker can write data beyond the allocated memory buffer, potentially overwriting adjacent memory regions that contain critical system structures or security controls. The vulnerability operates at the kernel level within the hardware composer module, making it accessible to any process running with standard user privileges.
The operational impact of CVE-2018-9409 extends beyond typical memory corruption scenarios due to its privilege escalation potential. Since exploitation requires no user interaction and can be achieved with existing system privileges, it represents a significant threat to Android device security. Attackers can leverage this vulnerability to gain elevated privileges within the system, potentially enabling them to access sensitive data, modify system configurations, or even install malicious software that operates at the kernel level. The hardware composer module typically runs with high privileges to manage display hardware directly, making this particular vulnerability a prime target for attackers seeking to establish persistent control over affected devices.
This vulnerability aligns with CWE-129, which specifically addresses insufficient validation of length of inputs to ensure they are within acceptable bounds. The flaw also corresponds to ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation' and demonstrates how memory corruption vulnerabilities can be exploited to gain elevated system privileges. The attack vector for this vulnerability is particularly concerning because it operates without requiring user interaction, meaning that malicious code could be executed silently in the background. The absence of user interaction requirements significantly increases the attack surface and makes this vulnerability particularly attractive to threat actors seeking to compromise Android devices at scale.
Mitigation strategies for CVE-2018-9409 should focus on immediate patch deployment from device manufacturers, as this vulnerability affects multiple Android versions including those from Android 5.0 through 8.1. The most effective remediation involves implementing proper bounds checking in the SetColorModeById function to validate input parameters before memory operations occur. Additionally, system administrators should ensure that devices receive timely security updates and consider implementing runtime protections such as address space layout randomization and stack canaries to make exploitation more difficult. Organizations should also conduct comprehensive vulnerability assessments to identify other potential memory corruption flaws in similar hardware abstraction layers, as this pattern of insufficient input validation may exist elsewhere in the system. The vulnerability highlights the importance of rigorous code review processes for kernel-level components and emphasizes the need for comprehensive security testing of hardware abstraction layers that operate with elevated privileges.