CVE-2018-11987 in Android
Summary
by MITRE
In all android releases(Android for MSM, Firefox OS for MSM, QRD Android) from CAF using the linux kernel, if there is an unlikely memory alloc failure for the secure pool in boot, it can result in wrong pointer access causing kernel panic.
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Analysis
by VulDB Data Team • 04/22/2020
The vulnerability identified as CVE-2018-11987 represents a critical kernel-level memory management flaw affecting multiple Android variants including MSM-based devices, Firefox OS for MSM, and QRD Android implementations. This issue stems from the Linux kernel's handling of secure memory pools during the boot process, where an improbable memory allocation failure triggers a dangerous pointer access pattern that ultimately results in system kernel panic. The vulnerability specifically targets the secure memory allocation mechanisms that are essential for maintaining system integrity during early boot phases when memory resources are critically limited and the kernel's memory management subsystem is under significant stress.
The technical root cause of this vulnerability lies in the improper handling of memory allocation failures within the secure pool management system. When memory allocation for the secure pool encounters an unlikely failure condition during boot initialization, the kernel's memory management code fails to properly validate pointer references before accessing memory locations. This leads to a classic null pointer dereference or invalid memory access pattern that causes the kernel to crash and terminate the boot process entirely. The vulnerability is classified under CWE-476 as a NULL pointer dereference, though it manifests specifically within the secure memory allocation context rather than general pointer handling. The flaw demonstrates poor error handling practices in kernel memory management code where allocation failure conditions are not adequately protected against subsequent pointer access operations.
The operational impact of CVE-2018-11987 extends beyond simple system instability to potentially compromise device availability and security posture. During the critical boot phase, any kernel panic caused by this vulnerability results in complete device failure, preventing normal system operation and potentially leaving devices in an unbootable state. This represents a significant availability risk that could be exploited by attackers to perform denial-of-service attacks against affected devices. The vulnerability affects all Android releases from Code Aurora Forum (CAF) that utilize the Linux kernel, making it widespread across numerous device implementations. From an ATT&CK framework perspective, this vulnerability aligns with T1499.004 (Authorization Script Execution) and T1566.001 (Phishing) as potential attack vectors, though its primary impact remains as a system availability threat rather than a direct security compromise.
Mitigation strategies for CVE-2018-11987 require immediate patching of affected kernel implementations through firmware updates from device manufacturers. Organizations should prioritize updating all affected devices to versions containing the patched kernel memory management code that properly handles allocation failure conditions without proceeding to invalid pointer access operations. The fix typically involves implementing proper error checking and validation mechanisms within the secure memory pool allocation code to ensure that pointer references are only accessed when allocation succeeds, or that appropriate fallback mechanisms are in place when allocation fails. Security teams should also consider monitoring for system panic events and boot failures that may indicate exploitation attempts, while maintaining awareness of the vulnerability's potential for being weaponized in targeted attacks against specific device populations. Device manufacturers should implement comprehensive testing procedures for memory allocation failure scenarios during boot processes to prevent similar issues from emerging in future implementations.