CVE-2026-58848 in Android
Summary
by MITRE • 09/09/2026
In multiple functions of alloc.c, there is a possible unauthorized read/write access due to a race condition. 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 • 09/09/2026
The vulnerability described involves a critical race condition within the memory allocation subsystem, specifically located in multiple functions of alloc.c. This flaw stems from improper synchronization mechanisms when handling concurrent access to shared data structures or resources during dynamic memory operations. In operating system kernels and low-level system libraries, memory management routines are frequently invoked by various processes simultaneously. When these routines fail to properly lock or serialize access to critical sections, a race condition emerges where the state of the allocated memory can be altered between the time it is checked for validity and the time it is actually used. This temporal gap allows an attacker to manipulate the allocation context, potentially causing the system to read from or write to memory locations that were not intended for such access.
From a technical perspective, this race condition represents a classic Time-of-Check-to-Time-of-Use (TOCTOU) vulnerability. The core issue lies in the lack of atomic operations when verifying and utilizing allocated memory blocks. An attacker can exploit this by triggering multiple concurrent allocation requests that target the same resource or adjacent memory regions. By carefully timing these requests, the attacker can cause the kernel to dereference pointers based on stale information, leading to unauthorized reads or writes. This type of flaw is particularly dangerous because it does not require complex buffer overflow techniques; instead, it relies on precise concurrency manipulation and knowledge of the system's internal allocation patterns.
The operational impact of this vulnerability is severe, primarily due to its potential for local privilege escalation. Since the race condition occurs within kernel-space memory management functions, successful exploitation allows an unprivileged user to gain control over critical system structures or execute arbitrary code with elevated privileges. The description notes that no additional execution privileges are needed, meaning any standard user account on the affected system can attempt this attack. Furthermore, because user interaction is not required for exploitation, the vulnerability can be triggered remotely if there is a network-facing service that invokes these allocation functions, or locally by any process running under the same user context. This significantly lowers the barrier to entry for attackers and increases the likelihood of successful compromise in multi-tenant environments or shared hosting scenarios.
In terms of industry standards classification, this vulnerability aligns with CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). The specific behavior of reading from or writing to unauthorized memory locations also maps closely to CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer. From an offensive security perspective, this technique is consistent with ATT&CK tactic Tactic TA0004: Privilege Escalation and specifically relates to techniques involving kernel exploitation or driver abuse where race conditions are leveraged to bypass access controls. The ability to escalate privileges without additional execution privileges highlights the severity of the flaw in the context of defense-in-depth strategies, as it undermines the fundamental isolation between user-space applications and kernel-space resources.
Mitigation for this vulnerability requires a comprehensive review of the alloc.c implementation to ensure all shared resources are properly synchronized. Developers must implement robust locking mechanisms, such as spinlocks or mutexes, around critical sections that handle memory allocation and deallocation. It is essential to verify that these locks cover both the check phase and the use phase of any resource access to prevent TOCTOU scenarios. Additionally, adopting atomic operations where possible can reduce the window of vulnerability inherent in race conditions. System administrators should apply vendor-provided patches immediately upon release. For environments where patching may be delayed, implementing strict process isolation policies and limiting user privileges can help mitigate the risk of exploitation by reducing the attack surface available to potential adversaries.