CVE-2016-3757 in Android
Summary
by MITRE
The print_maps function in toolbox/lsof.c in Android 4.x before 4.4.4, 5.0.x before 5.0.2, 5.1.x before 5.1.1, and 6.x before 2016-07-01 allows user-assisted attackers to gain privileges via a crafted application that attempts to list a long name of a memory-mapped file, aka internal bug 28175237. NOTE: print_maps is not related to the Vic Abell lsof product.
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Analysis
by VulDB Data Team • 09/14/2025
The vulnerability described in CVE-2016-3757 represents a privilege escalation flaw within the Android operating system's lsof implementation, specifically affecting versions prior to the mentioned security patches. This issue resides in the print_maps function located within toolbox/lsof.c, which is part of the Android system utilities that provide process and file descriptor information. The vulnerability manifests when a malicious application attempts to list memory-mapped files with excessively long names, creating a condition that can be exploited by user-assisted attackers to elevate their privileges within the system.
The technical root cause of this vulnerability stems from insufficient input validation and buffer handling within the print_maps function. When processing memory-mapped file names that exceed expected length parameters, the function fails to properly sanitize or limit the input, leading to potential buffer overflow conditions or memory corruption scenarios. This flaw falls under the CWE-121 category of Stack-based Buffer Overflow, where the system's memory management fails to properly handle oversized inputs during the mapping process. The vulnerability is particularly concerning because it operates within the toolbox utilities that are typically accessible to regular users, making it exploitable through legitimate application execution paths rather than requiring pre-existing elevated privileges.
From an operational perspective, this vulnerability creates a significant security risk as it allows attackers to escalate privileges from standard user-level applications to system-level access. The attack vector requires user interaction, meaning a malicious application must be installed and executed by the victim, but once triggered, the privilege escalation can enable full system compromise. The vulnerability affects multiple Android versions including 4.x through 6.x, indicating a widespread impact across the platform's ecosystem. Attackers can leverage this flaw to gain access to sensitive system resources, read protected files, modify system configurations, or potentially install additional malicious software. The impact extends beyond individual device security to potentially affect enterprise environments where Android devices are used for business operations.
The exploitation of this vulnerability aligns with techniques described in the MITRE ATT&CK framework under privilege escalation tactics, specifically targeting the execution of malicious code with elevated privileges. Organizations should implement immediate mitigations including applying the relevant Android security patches released in July 2016, which addressed the buffer handling issues in the lsof implementation. System administrators should also consider monitoring for suspicious application behavior related to memory mapping operations and implement application whitelisting policies to prevent unauthorized applications from executing potentially malicious code. Additionally, regular security assessments should verify that all Android devices within the organization have received the necessary updates, as this vulnerability represents a persistent risk that could be exploited by attackers with access to victim devices. The vulnerability demonstrates the importance of proper input validation and buffer management in system utilities, particularly those that operate with elevated privileges or handle user-provided data in potentially untrusted contexts.