CVE-2018-9490 in Android
Summary
by MITRE
In CollectValuesOrEntriesImpl of elements.cc, there is possible remote code execution due to type confusion. This could lead to remote escalation of privilege with no additional execution privileges needed. User interaction is needed for exploitation. Product: AndroidVersions: Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android-9.0 Android ID: A-111274046
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Analysis
by VulDB Data Team • 03/29/2020
The vulnerability identified as CVE-2018-9490 represents a critical type confusion flaw within the Android operating system's JavaScript engine implementation. This issue resides in the CollectValuesOrEntriesImpl function located in elements.cc, which forms part of the V8 JavaScript engine used by Android's web rendering capabilities. The vulnerability stems from improper type handling during JavaScript object manipulation, creating conditions where an attacker can manipulate object types in unexpected ways. This type confusion allows for memory corruption that can be exploited to execute arbitrary code with elevated privileges, potentially leading to complete system compromise.
The technical exploitation of this vulnerability requires a specific attack vector through web-based content execution. An attacker must first deliver malicious JavaScript code to a target device, typically through phishing emails, compromised websites, or malicious advertisements. The vulnerability requires user interaction to trigger, meaning the victim must visit a malicious webpage or open a compromised email attachment containing the malicious JavaScript payload. Once executed, the type confusion in the V8 engine's object handling mechanism allows attackers to manipulate memory layout and execute arbitrary code with system-level privileges. This represents a remote code execution vulnerability that can be leveraged without requiring any additional privileges or access to the device.
The operational impact of CVE-2018-9490 extends across multiple Android versions including Android 7.0, 7.1.1, 7.1.2, 8.0, 8.1, and 9.0, affecting a significant portion of the Android user base at the time of disclosure. The vulnerability's classification as a remote code execution flaw with privilege escalation capabilities makes it particularly dangerous for enterprise and individual users alike. The attack surface includes all Android devices that render web content through the affected JavaScript engine, which encompasses mobile browsers, email clients, and any application that integrates web rendering capabilities. This vulnerability directly maps to CWE-129, which describes improper validation of array indices, and aligns with ATT&CK techniques involving privilege escalation and code execution through browser-based attacks. The vulnerability's exploitation path typically involves crafting malicious JavaScript that triggers the type confusion during object manipulation, potentially leading to full system compromise.
Mitigation strategies for CVE-2018-9490 primarily focus on timely patching and system updates. Android users should immediately install the security patches released by Google, which include fixes to the V8 JavaScript engine's object handling mechanisms. Organizations should implement proactive patch management policies to ensure all Android devices receive security updates promptly. Network administrators can deploy web filtering solutions to block known malicious domains and content that may contain exploitation attempts. Additionally, browser security settings should be configured to limit JavaScript execution in untrusted environments, and users should be educated about the risks of visiting untrusted websites or opening suspicious email attachments. The vulnerability serves as a reminder of the critical importance of maintaining up-to-date security patches and the potential for remote code execution vulnerabilities to provide attackers with complete system access.