CVE-2017-0557 in Android
Summary
by MITRE
An information disclosure vulnerability in libmpeg2 in Mediaserver could enable a local malicious application to access data outside of its permission levels. This issue is rated as Moderate because it could be used to access data without permission. Product: Android. Versions: 6.0, 6.0.1, 7.0, 7.1.1. Android ID: A-34093073.
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Analysis
by VulDB Data Team • 11/27/2022
The vulnerability identified as CVE-2017-0557 represents a critical information disclosure flaw within the libmpeg2 library component of Android's Mediaserver service. This issue manifests as a privilege escalation vulnerability that allows local malicious applications to bypass normal access controls and retrieve data that should be restricted to higher permission levels. The vulnerability specifically affects Android versions 6.0, 6.0.1, 7.0, and 7.1.1, making it a widespread concern across multiple Android releases. The flaw resides in how the Mediaserver processes MPEG2 video data, creating a pathway for unauthorized data access that violates fundamental security principles of information access control.
The technical nature of this vulnerability stems from improper input validation and memory management within the libmpeg2 library implementation. When processing specially crafted MPEG2 video files, the library fails to properly bounds-check memory accesses or validate data structures, leading to potential buffer overflows or information leaks. This type of flaw falls under the CWE-125 vulnerability category, which describes out-of-bounds read conditions that can expose sensitive data. The vulnerability operates at the system level through the Mediaserver service, which runs with elevated privileges and handles multimedia processing tasks for various applications. Attackers can exploit this weakness by creating malicious media files that trigger the vulnerable code path when processed by the system, potentially allowing them to read memory contents that contain sensitive information such as application data, user credentials, or other confidential system resources.
The operational impact of CVE-2017-0557 extends beyond simple data disclosure, as it creates a persistent security risk that can be leveraged for further exploitation. An attacker with local access to an affected Android device can use this vulnerability to gather sensitive information that would normally be protected by the operating system's security model. The vulnerability's classification as Moderate severity reflects its potential to be weaponized for more sophisticated attacks, including credential theft, data exfiltration, or privilege escalation to system-level access. This issue directly impacts the Android security model by undermining the principle of least privilege, where applications should only have access to resources necessary for their operation. The vulnerability's presence in Mediaserver means that any application with the ability to create or process media files could potentially exploit this flaw, making it particularly dangerous in environments where untrusted media content might be processed.
Mitigation strategies for CVE-2017-0557 require both immediate patching and operational security measures to protect affected systems. Android security updates released in response to this vulnerability addressed the underlying memory handling issues in the libmpeg2 library, implementing proper bounds checking and input validation to prevent unauthorized data access. Organizations should prioritize applying the relevant security patches to all affected Android versions, with particular attention to devices running Android 6.0 through 7.1.1. The remediation process involves updating the system libraries that contain the vulnerable code, which typically requires device firmware updates or full system upgrades. Additional defensive measures include implementing application sandboxing policies that restrict media file processing capabilities, monitoring for suspicious media file handling activities, and ensuring that only trusted applications can process multimedia content. Security teams should also consider implementing network-based monitoring to detect potential exploitation attempts and establish incident response procedures for handling information disclosure events. This vulnerability highlights the importance of secure coding practices and proper input validation in system-level libraries, particularly those handling multimedia data processing that operates with elevated privileges. The issue demonstrates how vulnerabilities in foundational system components can create widespread security implications across entire operating system families.