CVE-2018-9459 in Android
Summary
by MITRE
In Attachment of Attachment.java and getFilePath of EmlAttachmentProvider.java, there is a possible Elevation of Privilege due to a path traversal error. This could lead to a remote escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation. Product: Android Versions: Android-6.0 Android-6.0.1 Android-7.0 Android-7.1.1 Android-7.1.2 Android-8.0 Android-8.1 Android ID: A-66230183.
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Analysis
by VulDB Data Team • 06/04/2023
The vulnerability identified as CVE-2018-9459 represents a critical elevation of privilege flaw within Android's email attachment handling mechanisms. This issue stems from improper validation of file paths during the processing of email attachments, specifically affecting the Attachment.java and EmlAttachmentProvider.java components. The vulnerability manifests as a path traversal error that allows malicious actors to manipulate file system access patterns and potentially execute arbitrary code with elevated privileges. The flaw exists in multiple Android versions including 6.0, 6.0.1, 7.0, 7.1.1, 7.1.2, 8.0, and 8.1, indicating a widespread impact across the Android ecosystem. The path traversal vulnerability enables attackers to bypass normal file system access controls and navigate to restricted directories, potentially gaining access to sensitive system files or executing malicious code with higher privileges than initially granted.
The technical exploitation of this vulnerability occurs through carefully crafted email attachments that contain malicious path traversal sequences. When the Android email client processes these attachments, the flawed implementation in Attachment.java and EmlAttachmentProvider.java fails to properly sanitize or validate the file paths, allowing attackers to manipulate the file system navigation. This type of vulnerability maps directly to CWE-22, which defines path traversal or directory traversal vulnerabilities that occur when input data is not properly validated before being used in file system operations. The flaw essentially allows attackers to access files outside of the intended directory structure, potentially enabling them to read system configuration files, modify critical application data, or even execute code with system-level privileges. The vulnerability does not require any user interaction for exploitation, making it particularly dangerous as it can be triggered automatically when email attachments are processed.
The operational impact of CVE-2018-9459 extends beyond simple privilege escalation to encompass potential data compromise and system integrity violations. An attacker exploiting this vulnerability could gain access to sensitive user data, system configuration files, or even escalate to full system control without requiring additional execution privileges. The vulnerability's presence in multiple Android versions suggests that a significant portion of the mobile device population could be affected, particularly in enterprise environments where email systems are extensively used. This flaw could be leveraged in targeted attacks against specific users or organizations, potentially enabling the theft of confidential information, installation of persistent backdoors, or complete system compromise. The lack of user interaction requirements means that automated attacks could be deployed without the need for social engineering or user deception, making this vulnerability particularly dangerous in mobile threat landscapes.
Mitigation strategies for CVE-2018-9459 should focus on immediate patch deployment and implementation of additional security controls. Android users and administrators should prioritize updating to patched versions of the operating system, as Google released security updates addressing this specific vulnerability. Organizations should implement email filtering solutions that can detect and block suspicious attachment patterns that may exploit path traversal vulnerabilities. Network-level security controls should include monitoring for unusual file access patterns and implementing strict file system access controls. From a defensive perspective, the vulnerability aligns with ATT&CK technique T1068, which covers 'Exploitation for Privilege Escalation,' and T1190, which addresses 'Exploit Public-Facing Application.' Security teams should also consider implementing application whitelisting policies for email clients and ensuring that file system access is properly restricted through proper input validation and sanitization mechanisms. Regular security assessments of email processing components and comprehensive monitoring of file system access patterns should be implemented to detect potential exploitation attempts.