CVE-2017-13232 in Android
Summary
by MITRE
In audioserver, there is an out-of-bounds write due to a log statement using %s with an array that may not be NULL terminated. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android. Versions: 5.1.1, 6.0, 6.0.1, 7.0, 7.1.1, 7.1.2, 8.0, 8.1. Android ID: A-68953950.
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Analysis
by VulDB Data Team • 02/03/2021
The vulnerability identified as CVE-2017-13232 resides within the audioserver component of Android operating systems, representing a critical out-of-bounds write flaw that stems from improper handling of log statements. This issue specifically manifests when the system employs the %s format specifier with an array that may not be null-terminated, creating a dangerous condition where memory access extends beyond allocated boundaries. The flaw exists in Android versions spanning from 5.1.1 through 8.1, indicating a widespread impact across multiple release branches and highlighting the severity of the underlying code issue.
The technical root cause of this vulnerability aligns with CWE-121, which describes stack-based buffer overflow conditions, and more specifically relates to CWE-787, out-of-bounds write vulnerabilities. The audioserver process, which manages audio-related services and system interactions, processes log data containing potentially unterminated strings during normal operation. When the logging mechanism attempts to format these strings using standard printf-style functions with %s specifiers, it assumes null termination of the character array, but this assumption fails when the array lacks proper termination. This mismanagement creates an exploitable condition where adjacent memory locations can be overwritten or accessed inappropriately.
The operational impact of this vulnerability extends beyond simple memory corruption, as it enables local information disclosure without requiring any additional privileges or user interaction for exploitation. Attackers can leverage this flaw to extract sensitive data from the system's memory space, potentially accessing audio configuration details, system identifiers, or other confidential information processed by the audioserver. The lack of user interaction requirements makes this vulnerability particularly concerning as it can be triggered automatically during normal system operations, such as audio processing or logging activities. The exploitation process involves crafting specific audio inputs or system conditions that cause the vulnerable code path to execute, resulting in memory corruption that reveals previously inaccessible data.
Mitigation strategies for CVE-2017-13232 should focus on both immediate patching and defensive programming practices. Android security updates addressed this issue through code modifications that ensure proper null termination of arrays before log formatting operations, effectively preventing the out-of-bounds memory access. Organizations should prioritize applying the latest Android security patches, particularly for devices running affected versions including 5.1.1, 6.0, 6.0.1, 7.0, 7.1.1, 7.1.2, 8.0, and 8.1. Additionally, developers should implement defensive programming techniques such as using safe string functions, validating array boundaries, and ensuring proper null termination before string operations. The vulnerability demonstrates the importance of adhering to secure coding practices and following ATT&CK framework considerations for privilege escalation and information disclosure tactics, as this flaw could potentially serve as a foothold for more sophisticated attacks targeting audio system components and broader system information.