CVE-2015-6642 in Android
Summary
by MITRE
The kernel in Android before 5.1.1 LMY49F and 6.0 before 2016-01-01 allows attackers to obtain sensitive information, and consequently bypass an unspecified protection mechanism, via unknown vectors, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bug 24157888.
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Analysis
by VulDB Data Team • 07/02/2022
The vulnerability identified as CVE-2015-6642 represents a critical information disclosure flaw within the Android kernel affecting versions prior to 5.1.1 LMY49F and 6.0 before the 2016-01-01 security patch release. This vulnerability operates at the kernel level, which provides attackers with unprecedented access to sensitive system information that can be leveraged to bypass crucial security protections. The flaw is particularly concerning because it enables attackers to obtain Signature or SignatureOrSystem access, which represents a significant escalation in privileges and access control bypass capability. The vulnerability was internally tracked as bug 24157888, indicating its recognition within Google's security team prior to public disclosure. The unspecified attack vectors suggest that this flaw could be exploited through multiple pathways, making it particularly dangerous as attackers can potentially identify and utilize various methods to exploit the vulnerability.
The technical implementation of this vulnerability stems from improper access control mechanisms within the kernel's security framework. When examining this issue through the lens of CWE classification, it aligns with CWE-284: Improper Access Control, which specifically addresses weaknesses where the system fails to properly enforce access restrictions. The kernel's protection mechanisms that should have prevented unauthorized access to sensitive information are bypassed, allowing attackers to obtain information that should remain restricted. This type of vulnerability typically involves flaws in privilege management, where the kernel fails to properly validate access requests or maintain proper isolation between different security domains. The attack surface is expanded because the vulnerability affects core kernel functionality that governs how applications and system components interact with protected resources.
The operational impact of CVE-2015-6642 extends far beyond simple information disclosure, as it creates a pathway for attackers to escalate privileges and gain unauthorized access to sensitive system components. When attackers can obtain Signature or SignatureOrSystem access, they essentially gain the ability to operate with the same privileges as system applications that are granted elevated permissions. This access level allows them to bypass application sandboxing, access protected system resources, and potentially install malicious software that can persist across system reboots. The vulnerability also has implications for the Android security model, as it undermines the principle of least privilege and allows attackers to circumvent the application permission system. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and can be used to achieve initial access through information gathering and subsequently maintain persistence through elevated privileges.
Mitigation strategies for CVE-2015-6642 primarily focus on system updates and patch management, as the most effective solution involves applying the security patches released by Google for Android versions 5.1.1 and 6.0. Organizations should prioritize immediate deployment of these patches across all affected devices to prevent exploitation. Additionally, security monitoring should be enhanced to detect anomalous access patterns that might indicate exploitation attempts, particularly around signature verification and system access requests. Network administrators should implement security controls to prevent unauthorized device access and ensure that only patched and verified devices can access corporate networks. The vulnerability also highlights the importance of maintaining current security practices, including regular security audits, proper device management policies, and ensuring that all system components are kept up to date with the latest security patches. Given that this vulnerability affects core kernel functionality, organizations should also consider implementing additional security layers such as application whitelisting and enhanced monitoring of system calls to detect potential exploitation attempts.