CVE-2014-9799 in Android
Summary
by MITRE
The makefile in the Qualcomm components in Android before 2016-07-05 on Nexus 5 and 7 (2013) devices omits the -fno-strict-overflow option to gcc, which might allow attackers to gain privileges via a crafted application that leverages incorrect compiler optimization of an integer-overflow protection mechanism, aka Android internal bug 28821731 and Qualcomm internal bug CR691916.
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Analysis
by VulDB Data Team • 09/01/2022
The vulnerability described in CVE-2014-9799 represents a critical compiler optimization flaw that existed in the Qualcomm components of Android operating systems prior to July 5, 2016, specifically affecting Nexus 5 and Nexus 7 (2013) devices. This issue stems from the absence of the -fno-strict-overflow compiler flag in the makefile configuration, which fundamentally alters how the gcc compiler handles integer overflow optimizations. The omission creates a scenario where the compiler makes incorrect assumptions about overflow behavior, potentially leading to security exploits that bypass intended protection mechanisms. This vulnerability operates at the foundational level of software compilation and optimization, making it particularly dangerous as it affects the very tools used to build the operating system components.
The technical flaw manifests through incorrect compiler optimization of integer overflow protection mechanisms, which falls under CWE-195, Integer Sign Error, and CWE-190, Integer Overflow or Wraparound. When the -fno-strict-overflow flag is omitted, the compiler applies aggressive optimizations that assume certain overflow conditions will not occur, creating a false sense of security in the compiled code. Attackers can exploit this by crafting malicious applications that specifically target these incorrect optimization assumptions, potentially causing the system to execute unintended code paths that lead to privilege escalation. The vulnerability exploits the inherent conflict between compiler performance optimizations and security assumptions, where aggressive optimization can undermine the intended security boundaries of the system. This type of vulnerability is particularly insidious because it exists in the compilation process itself rather than in the application code, making it difficult to detect and remediate through traditional code analysis approaches.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it represents a fundamental weakness in the Android security model that could be leveraged to compromise the entire device. The attack vector requires a crafted application, which aligns with ATT&CK technique T1068, Exploitation for Privilege Escalation, and potentially T1059, Command and Scripting Interpreter, when the exploited code executes. This vulnerability affects devices that were widely deployed and supported by Google, meaning that the attack surface was substantial across numerous users and installations. The fact that this issue was present in the Qualcomm components of Android highlights the complex interdependencies between hardware vendors and operating system developers in security assurance. The vulnerability's existence in the build system rather than runtime code means that exploitation could occur even on devices that were otherwise properly patched, making it particularly concerning for security professionals managing legacy Android deployments.
Mitigation strategies for this vulnerability require addressing the root cause in the build environment rather than attempting to patch runtime behavior. Organizations should ensure that all Android components are compiled with the proper -fno-strict-overflow flag to prevent the incorrect optimization assumptions that enable exploitation. This requires updating build configurations and ensuring that all Qualcomm components are rebuilt with appropriate compiler flags. The vulnerability demonstrates the importance of compiler security flags in preventing optimization-related security issues, which aligns with security best practices outlined in the CWE database for integer overflow prevention. System administrators should also implement comprehensive monitoring for unauthorized application installations that might attempt to exploit this vulnerability, while maintaining awareness of the specific device models and Android versions affected. Regular security audits of build processes and compiler configurations should be conducted to prevent similar issues from emerging in future development cycles, particularly as modern development environments continue to rely heavily on aggressive compiler optimizations that may inadvertently introduce security weaknesses.