CVE-2019-9248 in Android
Summary
by MITRE
In the Android kernel in the FingerTipS touchscreen driver there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/13/2023
The vulnerability identified as CVE-2019-9248 resides within the Android kernel's FingerTipS touchscreen driver implementation, representing a critical security flaw that undermines system integrity and privilege management. This issue manifests as a missing bounds check that enables an out-of-bounds write condition, fundamentally compromising the kernel's memory management mechanisms. The vulnerability specifically affects the touchscreen driver's handling of input data structures, where insufficient validation allows maliciously crafted input to overwrite adjacent memory regions beyond the intended buffer boundaries.
The technical exploitation of this vulnerability leverages the absence of proper input validation within the driver's data processing routines. When the FingerTipS touchscreen driver receives input data from hardware devices, it fails to verify that the data length conforms to expected parameters before writing to memory locations. This missing bounds check creates a scenario where an attacker can manipulate input parameters to cause memory corruption, potentially overwriting critical kernel data structures or function pointers. The flaw operates at the kernel level, making it particularly dangerous as it can be exploited without requiring user interaction or physical access to the device.
The operational impact of this vulnerability extends significantly beyond typical application-level security issues, as it provides a pathway for local privilege escalation to system-level privileges. An attacker with local execution capabilities can exploit this vulnerability to gain system execution privileges, effectively elevating their access level from regular user to root or system-level access. This privilege escalation occurs silently without any user interaction requirements, making the vulnerability particularly insidious and difficult to detect. The exploitation process typically involves crafting specific input sequences that trigger the out-of-bounds write condition, potentially leading to arbitrary code execution within the kernel context.
From a cybersecurity perspective, this vulnerability aligns with CWE-129, which addresses insufficient validation of length of input data, and represents a classic example of a buffer overflow condition within kernel space. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the 'Exploitation for Privilege Escalation' tactic. The vulnerability's classification as a kernel-level flaw places it within the high-risk category of security vulnerabilities that can compromise entire operating systems. Mitigation strategies must include immediate kernel updates and patches provided by device manufacturers, along with potential kernel hardening measures such as stack canaries and memory protection mechanisms. Organizations should implement comprehensive monitoring for unusual kernel behavior and ensure that all Android devices receive timely security updates to prevent exploitation of this critical vulnerability.