CVE-2015-3840 in Android
Summary
by MITRE
The MessageStatusReceiver service in the AndroidManifest.XML in Android 5.1.1 and earlier allows local users to alter sent/received statuses of SMS and MMS messages without the associated "WRITE_SMS" permission.
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Analysis
by VulDB Data Team • 10/20/2019
The vulnerability described in CVE-2015-3840 represents a critical privilege escalation issue within the Android messaging framework that affects versions 5.1.1 and earlier. This flaw resides in the MessageStatusReceiver service component which is defined in the AndroidManifest.xml configuration file, making it a fundamental part of the system's security architecture. The vulnerability stems from improper permission validation within the messaging subsystem where the service fails to properly verify whether the calling application possesses the necessary WRITE_SMS permission before allowing modifications to SMS and MMS message statuses. This design flaw creates a pathway for malicious local applications to manipulate message status indicators without proper authorization, effectively bypassing the Android security model's permission enforcement mechanisms.
The technical implementation of this vulnerability exploits the lack of proper access control validation within the Android messaging service architecture. When applications attempt to modify message status information through the MessageStatusReceiver, the system should verify that the requesting component has been granted the WRITE_SMS permission as mandated by Android's permission model. However, due to the flaw in the AndroidManifest.xml configuration, this verification process is either completely bypassed or inadequately implemented, allowing any local application to manipulate message status flags regardless of its permission level. This represents a direct violation of the principle of least privilege and demonstrates a failure in the Android security framework's mandatory access control mechanisms. The vulnerability specifically targets the status modification functionality for both SMS and MMS messages, which are critical components of the messaging infrastructure that track delivery confirmation and read status information.
From an operational impact perspective, this vulnerability enables attackers to manipulate message status indicators in ways that could facilitate various malicious activities including social engineering attacks, phishing campaigns, and message tampering operations. An attacker with local access to a device could modify message status flags to make it appear that messages were delivered or read when they were not, or conversely, to hide the fact that messages were actually delivered or read. This manipulation capability could be exploited to create false impressions about message delivery status, potentially leading to successful social engineering attacks where victims might trust fraudulent communications based on false delivery indicators. The vulnerability also impacts the integrity of messaging applications and could compromise the trust model that users rely upon when communicating through SMS and MMS services. According to CWE classification, this vulnerability maps to CWE-284: Improper Access Control, which specifically addresses insufficient access control mechanisms that allow unauthorized access to resources or functionality. The flaw also aligns with ATT&CK technique T1068: Exploitation for Privilege Escalation, as it allows local users to gain elevated privileges through manipulation of system services.
The mitigation strategies for this vulnerability primarily involve system-level updates and security configuration adjustments. The most effective solution is the immediate deployment of Android security patches that address the permission validation flaw in the MessageStatusReceiver service. System administrators and device manufacturers should prioritize the application of these security updates to prevent exploitation. Additionally, users should be educated about the importance of keeping their devices updated and should be aware of suspicious applications that might attempt to manipulate messaging status indicators. Organizations implementing mobile device management solutions should consider additional monitoring and access control policies that can detect unauthorized modifications to messaging status information. The vulnerability highlights the importance of proper permission model enforcement and demonstrates the critical need for comprehensive security testing of system services that handle sensitive user data. Device manufacturers should implement more robust permission validation mechanisms and ensure that all system services properly validate caller permissions before allowing access to sensitive functionality. This vulnerability serves as a reminder of the importance of maintaining up-to-date security configurations and the necessity of thorough security auditing of system services that handle user data and privacy-sensitive operations.