CVE-2019-9245 in Android
Summary
by MITRE
In the Android kernel in the f2fs driver there is a possible out of bounds read due to a missing bounds check. This could lead to local information disclosure 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-2019-9245 resides within the Android kernel's f2fs (Flash-Friendly File System) driver implementation, representing a critical security flaw that exposes the system to unauthorized information disclosure. This issue manifests as a missing bounds check that allows for out-of-bounds read operations, fundamentally compromising the integrity of the file system's memory management mechanisms. The f2fs driver, designed specifically for flash storage devices to optimize performance and longevity, becomes a vector for potential exploitation when handling malformed input data structures.
The technical flaw stems from insufficient validation of array indices or buffer boundaries within the f2fs driver's code execution paths. When processing certain file system operations or metadata structures, the driver fails to verify that accessed memory locations remain within valid bounds, creating a scenario where malicious actors can craft specific inputs to trigger memory reads beyond allocated buffers. This vulnerability operates at the kernel level, requiring system execution privileges for exploitation but eliminating the need for user interaction, making it particularly dangerous as it can be triggered through automated system processes or legitimate file operations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially expose sensitive kernel memory contents including cryptographic keys, credential information, or other confidential data structures. Attackers leveraging this flaw can gain insights into the kernel's internal state, potentially enabling further exploitation techniques such as privilege escalation or information gathering for more sophisticated attacks. The absence of user interaction requirements means that exploitation can occur during normal system operation, making detection and prevention significantly more challenging for security administrators.
Mitigation strategies for CVE-2019-9245 should prioritize immediate patch deployment from device manufacturers and Android security teams, as the vulnerability exists within core kernel components that cannot be easily bypassed through user-space protections. System administrators should implement comprehensive monitoring for unusual file system access patterns and memory reads that could indicate exploitation attempts. The vulnerability aligns with CWE-129, which specifically addresses insufficient bounds checking in input validation, and represents a clear violation of the principle of least privilege in kernel space operations. Organizations should also consider implementing kernel memory protection mechanisms such as stack canaries, address space layout randomization, and kernel address space protection to reduce the effectiveness of potential exploitation attempts. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically targeting the kernel execution environment where such flaws can be leveraged to gain elevated system access and control over critical system resources.