CVE-2015-5903 in Watch
Summary
by MITRE
The kernel in Apple iOS before 9 allows local users to gain privileges or cause a denial of service (memory corruption) via unspecified vectors, a different vulnerability than CVE-2015-5868 and CVE-2015-5896.
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Analysis
by VulDB Data Team • 11/21/2024
The vulnerability identified as CVE-2015-5903 represents a critical security flaw within the kernel component of Apple iOS versions prior to 9.0, classified as a local privilege escalation vulnerability that could potentially lead to both unauthorized system access and system stability issues. This vulnerability specifically affects the kernel's handling of certain memory operations and system calls, creating opportunities for malicious actors to exploit kernel-level processes and manipulate system resources. The flaw operates at the most fundamental level of the operating system, where kernel memory management and process isolation mechanisms are compromised, allowing local attackers to execute arbitrary code with elevated privileges.
The technical nature of this vulnerability stems from improper memory handling within kernel space operations, where insufficient input validation and memory boundary checks create exploitable conditions that can result in memory corruption. Attackers can leverage these conditions to manipulate kernel memory structures, potentially leading to privilege escalation from standard user context to kernel-level privileges. This type of vulnerability typically involves race conditions, buffer overflows, or use-after-free scenarios within kernel subsystems that manage process creation, memory allocation, or system call processing. The unspecified vectors suggest that multiple attack surfaces within the kernel could be exploited, making the vulnerability particularly dangerous as it may not be easily predictable or patchable through targeted fixes.
The operational impact of CVE-2015-5903 extends beyond simple privilege escalation, as the memory corruption aspect can result in system instability and denial of service conditions that may crash the device or render it unusable. When exploited successfully, this vulnerability allows attackers to bypass the kernel's security mechanisms that normally prevent unauthorized access to system resources, potentially enabling full device compromise. The local nature of the exploit means that attackers must already have access to the device, typically through legitimate user accounts or other initial compromise vectors, but the privilege escalation capability makes the attack significantly more dangerous. This vulnerability aligns with CWE-119, which addresses "Improper Access to Memory" and represents a classic example of kernel memory corruption that can be leveraged for privilege escalation attacks.
The security implications of this vulnerability are particularly concerning given that iOS devices are designed to provide strong isolation between applications and system processes, with the kernel serving as the primary guardian of system integrity. When kernel-level memory corruption occurs, it fundamentally undermines the security model that iOS relies upon for protecting user data and maintaining system stability. This vulnerability may be exploited through various attack vectors including malicious applications, compromised system services, or through other initial compromise methods that allow local code execution. The memory corruption aspect can manifest in unpredictable system behavior, including crashes, data corruption, or complete system lockups that require device restarts to resolve, making this a particularly insidious threat to system reliability.
Mitigation strategies for CVE-2015-5903 primarily focus on upgrading to iOS version 9.0 or later, where Apple has implemented comprehensive fixes for the kernel memory handling issues. System administrators and users should prioritize immediate upgrades to the patched iOS versions, as the vulnerability remains exploitable in older releases. Additional protective measures include implementing strict application sandboxing policies, monitoring for unusual system behavior that may indicate exploitation attempts, and maintaining regular security updates for all iOS devices. The vulnerability demonstrates the importance of kernel-level security testing and the need for comprehensive memory safety validation in operating system components. Organizations should also consider implementing endpoint detection and response solutions that can monitor for signs of kernel exploitation attempts and provide early warning of potential compromise. This vulnerability serves as a reminder of the critical importance of maintaining up-to-date system software and the potential consequences of running unsupported operating system versions that may contain known security flaws.