CVE-2019-9247 in Android
Summary
by MITRE
In AAC Codec, there is a missing variable initialization. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-120426166
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Analysis
by VulDB Data Team • 09/12/2020
The vulnerability identified as CVE-2019-9247 resides within the Advanced Audio Coding AAC Codec implementation in Android operating systems, specifically affecting Android 10 and earlier versions. This weakness represents a critical security flaw that demonstrates poor software development practices and inadequate input validation mechanisms. The issue manifests as a missing variable initialization within the audio codec processing pipeline, creating a potential vector for information disclosure attacks that could compromise system security.
The technical flaw stems from a failure to properly initialize a variable within the AAC decoding process, which creates unpredictable behavior and potential information leakage. This uninitialized variable could contain residual data from previous operations or memory contents, leading to the exposure of sensitive information such as memory addresses, cryptographic keys, or other confidential data. The vulnerability falls under the CWE-457 category of "Use of Uninitialized Variable" which is classified as a common weakness in software security implementations. When the AAC codec processes audio data, the uninitialized variable may inadvertently reveal information about the system's memory state or internal operations.
Exploitation of this vulnerability requires user interaction, meaning an attacker must convince a victim to perform a specific action such as playing an audio file or accessing a malicious website that triggers the affected codec. This interaction requirement reduces the attack surface compared to fully autonomous exploits but does not eliminate the security risk. The attack vector typically involves crafting malicious audio content that, when processed by the vulnerable AAC decoder, causes the uninitialized variable to be exposed through error messages, debug output, or memory dumps. The lack of additional execution privileges required for exploitation makes this vulnerability particularly concerning as it can be leveraged by attackers without needing elevated system permissions.
The operational impact of CVE-2019-9247 extends beyond simple information disclosure, potentially enabling more sophisticated attacks that could lead to privilege escalation or system compromise. This vulnerability directly affects Android devices running Android 10 and earlier versions, creating a widespread security concern across numerous mobile platforms. The vulnerability is catalogued in the Android Security Bulletin and represents a significant weakness in the platform's media processing capabilities. Organizations and users should consider this vulnerability in their risk assessment frameworks, particularly in environments where mobile device security is paramount. The attack pattern aligns with ATT&CK technique T1059.007 for command and scripting interpreter, as the exploitation may involve manipulating audio processing to extract information through indirect means.
Mitigation strategies for CVE-2019-9247 primarily involve updating to patched Android versions where the uninitialized variable issue has been resolved through proper initialization practices. System administrators should prioritize deployment of security patches and updates to eliminate this vulnerability from affected devices. Additionally, implementing network-level controls such as content filtering and sandboxing audio processing capabilities can provide additional protection. Security monitoring should include detection of unusual audio processing patterns that might indicate exploitation attempts. The fix typically involves ensuring all variables are properly initialized before use, implementing proper input validation, and conducting thorough code reviews to prevent similar issues in future implementations. Organizations should also consider implementing device management policies that enforce automatic updates and regular security assessments to maintain protection against such vulnerabilities.