CVE-2024-23716 in Android
Summary
by MITRE • 09/11/2024
In DevmemIntPFNotify of devicemem_server.c, there is a possible use-after-free due to a race condition. This could lead to local escalation of privilege in the kernel with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 12/17/2024
The vulnerability identified as CVE-2024-23716 represents a critical use-after-free condition within the kernel-level device memory management subsystem of a Linux-based operating system. This flaw exists in the devicemem_server.c source file within the DevmemIntPFNotify function, where improper synchronization mechanisms fail to prevent concurrent access patterns that can result in memory corruption. The vulnerability specifically manifests when multiple threads or processes attempt to access device memory resources simultaneously, creating a race condition that allows for memory deallocation followed by subsequent access to the same memory region. This type of flaw falls under the Common Weakness Enumeration category CWE-416, which specifically addresses use-after-free vulnerabilities where memory is accessed after it has been freed by the system.
The exploitation of this vulnerability enables local privilege escalation without requiring any special user privileges or interaction, making it particularly dangerous as it can be leveraged by any local user to gain elevated system privileges. The kernel-level nature of the flaw means that successful exploitation would allow an attacker to execute arbitrary code with the highest system privileges, potentially leading to complete system compromise. The race condition occurs during the handling of page fault notifications for device memory access, where the kernel's memory management subsystem fails to properly synchronize access to shared data structures that control device memory mappings. This vulnerability aligns with ATT&CK technique T1068 which describes the exploitation of legitimate credentials and system privileges to gain elevated access, and specifically targets the kernel's memory management subsystem as outlined in ATT&CK technique T1543.
The operational impact of CVE-2024-23716 extends beyond simple privilege escalation as it represents a fundamental breakdown in the kernel's memory safety mechanisms. When the race condition occurs, the freed memory can be reallocated to other data structures or potentially reused by the kernel for legitimate operations, but the existing references to the freed memory location can cause unpredictable behavior including system crashes, data corruption, or more critically, execution of arbitrary code. The local nature of the exploitation means that attackers do not need network access or complex social engineering techniques to exploit this vulnerability, making it particularly attractive for attackers seeking to establish persistent access to compromised systems. The vulnerability affects systems where device memory access is enabled and where the kernel's device memory management subsystem is actively utilized, which includes servers, embedded systems, and any platform that requires direct hardware memory access for device drivers or system operations.
Mitigation strategies for this vulnerability should focus on immediate kernel updates from the vendor to address the race condition in the devicemem_server.c implementation. System administrators should prioritize patching affected systems as soon as vendor advisories are available, as the vulnerability does not require user interaction for exploitation and can be leveraged by any local user with basic system access. Additional defensive measures include implementing proper kernel memory management practices such as using proper locking mechanisms, ensuring atomic operations during memory allocation and deallocation, and conducting thorough code reviews for similar race conditions in kernel subsystems. The vulnerability also highlights the importance of maintaining up-to-date kernel security patches and implementing proper kernel hardening configurations including stack canaries, kernel address space layout randomization, and other exploit mitigation techniques that can reduce the effectiveness of potential exploitation attempts. Organizations should also consider monitoring for unusual memory access patterns or kernel-level anomalies that might indicate exploitation attempts, as the use-after-free condition could manifest in subtle ways before complete privilege escalation occurs.