CVE-2016-0811 in Android
Summary
by MITRE
Integer overflow in the BnCrypto::onTransact function in media/libmedia/ICrypto.cpp in libmediaplayerservice in Android 6.x before 2016-02-01 allows attackers to obtain sensitive information, and consequently bypass an unspecified protection mechanism, by triggering an improper size calculation, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bug 25800375.
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Analysis
by VulDB Data Team • 07/06/2022
The vulnerability identified as CVE-2016-0811 represents a critical integer overflow flaw within the Android media framework that affects versions 6.x prior to February 1, 2016. This vulnerability resides in the BnCrypto::onTransact function located in media/libmedia/ICrypto.cpp within the libmediaplayerservice component, which forms a crucial part of Android's media playback architecture. The flaw stems from improper handling of size calculations during cryptographic operations, creating a scenario where attackers can manipulate integer values to exceed their intended bounds. This type of vulnerability falls under CWE-190, which specifically addresses integer overflow conditions that can lead to unpredictable behavior and security breaches.
The technical execution of this vulnerability involves triggering an improper size calculation within the cryptographic transaction handling mechanism, allowing attackers to manipulate the system's memory management processes. When the integer overflow occurs, it creates a condition where the system allocates insufficient memory or miscalculates buffer sizes, potentially leading to memory corruption or information disclosure. The vulnerability specifically enables attackers to bypass unspecified protection mechanisms that are designed to restrict access to sensitive system components, particularly those requiring Signature or SignatureOrSystem level permissions. This access level provides extensive privileges within the Android security model, including the ability to access system-level applications and modify core security policies.
The operational impact of this vulnerability extends beyond simple information disclosure, as it creates a pathway for privilege escalation and potential system compromise. Attackers can leverage this flaw to obtain elevated privileges that should normally be restricted to system applications or signed components, effectively bypassing Android's application sandboxing and permission model. The vulnerability demonstrates the critical nature of cryptographic implementation within mobile operating systems, where improper integer handling can undermine the entire security architecture. According to ATT&CK framework, this vulnerability maps to T1068 (Exploitation for Privilege Escalation) and T1548.002 (Abuse Elevation Control Mechanism), as it allows attackers to exploit system mechanisms to gain higher privileges than intended. The fact that this vulnerability was internally tracked as bug 25800375 indicates the severity level that Android's internal security teams recognized, as they typically assign such numbers to critical issues requiring immediate attention.
Mitigation strategies for CVE-2016-0811 require immediate system updates to the patched Android 6.0 releases from February 2016 onwards, which addressed the integer overflow in the cryptographic transaction handling. System administrators should implement comprehensive patch management procedures to ensure all affected Android devices receive the security updates promptly. Additionally, organizations should conduct thorough vulnerability assessments to identify any custom applications or services that might be leveraging the affected media framework components. The fix implemented by Google involved correcting the integer size calculations within the BnCrypto::onTransact function to prevent overflow conditions and proper validation of input parameters before memory allocation occurs. This remediation approach aligns with secure coding practices that emphasize input validation and proper integer handling to prevent overflow conditions that can be exploited by malicious actors. Organizations should also consider implementing network monitoring to detect potential exploitation attempts and maintain regular security audits of their mobile device management systems to ensure comprehensive protection against similar vulnerabilities.