CVE-2015-5843 in Watch
Summary
by MITRE
IOMobileFrameBuffer in Apple iOS before 9 allows local users to gain privileges or cause a denial of service (memory corruption) via unspecified vectors.
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Analysis
by VulDB Data Team • 06/19/2022
The vulnerability identified as CVE-2015-5843 resides within the IOMobileFrameBuffer component of Apple iOS versions prior to 9.0, representing a critical security flaw that exposes devices to both privilege escalation and denial of service conditions. This component serves as a crucial interface for mobile frame buffer operations within the iOS kernel, managing graphics rendering and display functionality for mobile devices. The unspecified vectors through which this vulnerability can be exploited suggest that multiple attack surfaces within the frame buffer subsystem may have been compromised, potentially including improper memory handling, input validation failures, or race conditions during graphics processing operations. The vulnerability's classification as a local privilege escalation issue indicates that an attacker with limited user access could potentially leverage this flaw to execute code with kernel-level privileges, fundamentally compromising the device's security model. This represents a significant breach in Apple's security architecture, as the frame buffer subsystem operates at a low level within the operating system, making it an attractive target for attackers seeking to elevate their privileges without requiring physical access or complex exploitation techniques.
The technical implementation of this vulnerability involves memory corruption within the IOMobileFrameBuffer kernel extension, which directly impacts the iOS graphics subsystem's ability to manage display buffers and frame rendering operations. Memory corruption vulnerabilities of this nature typically arise from improper bounds checking, use-after-free conditions, or integer overflows within kernel code that handles graphics memory management. The frame buffer subsystem's interaction with hardware display controllers and graphics processing units creates multiple potential attack vectors where malicious code could manipulate memory structures to cause unexpected behavior. These memory corruption issues can manifest in various ways including stack overflows, heap corruption, or pointer dereference errors that ultimately lead to privilege escalation or system crashes. The vulnerability's presence in iOS versions before 9.0 indicates that Apple's security team had not yet addressed these specific memory handling issues in their kernel extensions, leaving millions of devices exposed to potential exploitation through local user access.
The operational impact of CVE-2015-5843 extends beyond simple denial of service conditions to encompass serious security implications for iOS users and organizations relying on mobile device security. Local privilege escalation capabilities mean that malicious applications or compromised user accounts could potentially gain root access to devices, enabling full system compromise and data exfiltration. This vulnerability particularly affects enterprise environments where iOS devices may be used for sensitive operations, as attackers could exploit this flaw to bypass device security controls, access encrypted data, or establish persistent backdoors. The memory corruption aspects also create potential for system instability and unexpected device shutdowns, which could be exploited for denial of service attacks against critical mobile services. Organizations using iOS devices for business operations face increased risk of data breaches and service disruption, as attackers could leverage this vulnerability to gain unauthorized access to corporate networks through compromised mobile endpoints. The widespread adoption of iOS devices across enterprise and consumer markets amplifies the potential impact, as the vulnerability affects a large user base with varying levels of security awareness and protection.
Mitigation strategies for CVE-2015-5843 primarily focus on immediate system updates and security hardening measures to prevent exploitation of the memory corruption vulnerability. Apple's release of iOS 9.0 addressed this vulnerability through kernel memory management improvements and enhanced input validation within the IOMobileFrameBuffer component. Organizations should prioritize immediate deployment of iOS 9.0 updates across all affected devices, as this represents the most effective defense against exploitation attempts. Additional mitigations include implementing mobile device management solutions that enforce security policies, monitoring for suspicious application behavior that could indicate exploitation attempts, and establishing incident response procedures for potential compromise detection. Security teams should also consider implementing network monitoring to detect potential exploitation attempts and establish baseline device behavior for anomaly detection. The vulnerability's classification aligns with CWE-121, which describes stack-based buffer overflow conditions, and may also relate to CWE-122 for heap-based buffer overflows, both of which are common in kernel-level memory management issues. From an ATT&CK perspective, this vulnerability maps to privilege escalation techniques and defense evasion methods, as attackers could use the flaw to maintain persistence and avoid detection within mobile environments. Regular security assessments and vulnerability scanning should be conducted to ensure all iOS devices remain protected against similar kernel-level vulnerabilities that may emerge in the future.