CVE-2015-6626 in Android
Summary
by MITRE
libstagefright in Android before 5.1.1 LMY48Z and 6.0 before 2015-12-01 allows remote attackers to obtain sensitive information, and consequently bypass an unspecified protection mechanism, via unknown vectors, as demonstrated by obtaining Signature or SignatureOrSystem access, aka internal bug 24310423.
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Analysis
by VulDB Data Team • 06/19/2018
The vulnerability identified as CVE-2015-6626 resides within the libstagefright multimedia framework component of Android operating systems, representing a critical information disclosure flaw that affected versions prior to Android 5.1.1 LMY48Z and Android 6.0 before the 2015-12-01 security patch release. This vulnerability specifically impacts the multimedia processing capabilities of Android devices, where the stagefright framework handles various media file formats and streaming protocols. The flaw enables remote attackers to exploit unknown vectors that ultimately allow them to obtain sensitive information from the system, effectively bypassing unspecified protection mechanisms that are designed to safeguard system integrity and user data.
The technical nature of this vulnerability stems from improper handling of multimedia data structures within the libstagefright library, which processes media files for playback and streaming operations. When processing maliciously crafted media files or streams, the framework fails to properly validate input data, leading to information disclosure that can reveal system-level access credentials or security tokens. This particular flaw manifests in the ability to escalate privileges and gain access to Signature or SignatureOrSystem level permissions, which are critical system-level access controls that provide applications with elevated privileges and access to protected system components. The vulnerability operates at the kernel level within the Android system, making it particularly dangerous as it can be exploited without user interaction through remote delivery methods.
The operational impact of CVE-2015-6626 extends beyond simple information disclosure, as it fundamentally compromises the security model of Android devices by enabling privilege escalation attacks. Attackers can leverage this vulnerability to bypass security protections that are typically enforced by the Android permission system, potentially allowing them to execute malicious code with system-level privileges. This capability directly violates the principle of least privilege and undermines the security architecture of Android, as demonstrated by the ability to obtain Signature or SignatureOrSystem access levels that are normally restricted to legitimate system applications and verified signatures. The vulnerability creates a persistent threat vector that can be exploited through various delivery mechanisms including email attachments, web downloads, or malicious media streams, making it particularly dangerous for widespread exploitation.
Security mitigations for this vulnerability involve applying the appropriate security patches released by Google as part of their regular security updates, specifically targeting the Android versions affected by this flaw. Organizations and users should ensure immediate deployment of the 2015-12-01 security patch or equivalent updates that address the information disclosure mechanisms within libstagefright. System administrators should implement network monitoring to detect potential exploitation attempts and consider implementing network segmentation to limit the potential impact of successful attacks. The vulnerability aligns with CWE-200, which addresses information exposure, and represents a significant concern under the ATT&CK framework's privilege escalation tactics, specifically targeting the use of system-level vulnerabilities to gain elevated access rights. Additionally, implementing application whitelisting and media file validation mechanisms can help reduce the attack surface, while regular security assessments should verify that all multimedia processing components are properly patched and configured according to industry best practices for mobile security.