CVE-2018-9581 in Android
Summary
by MITRE
In WiFi, the RSSI value and SSID information is broadcast as part of android.net.wifi.RSSI_CHANGE and android.net.wifi.STATE_CHANGE intents. This could lead to local information disclosure with no additional execution privileges needed. User interaction is not needed for exploitation. Product: AndroidVersions: Android-10Android ID: A-111698366
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Analysis
by VulDB Data Team • 12/28/2023
The vulnerability described in CVE-2018-9581 represents a significant information disclosure issue within the Android wireless networking subsystem that affects Android 10 and earlier versions. This flaw resides in how the Android operating system handles wireless network state changes, specifically in the broadcast mechanisms that communicate RSSI (Received Signal Strength Indicator) values and SSID (Service Set Identifier) information through system intents. The vulnerability is particularly concerning because it operates at the system level without requiring any special privileges or user interaction, making it accessible to any application running on the device. The affected components include the android.net.wifi.RSSI_CHANGE and android.net.wifi.STATE_CHANGE intent broadcasts that are fundamental to how Android applications monitor and respond to wireless network conditions.
The technical implementation of this vulnerability stems from the design decision to broadcast sensitive wireless network information through system-level intents that are accessible to all applications with appropriate permissions. When wireless network state changes occur, the system automatically sends these intents containing detailed information about the network environment including signal strength measurements and network identifiers. The RSSI values provide quantitative information about signal quality which can be used to infer network topology and potentially locate devices within specific geographical areas. The SSID information reveals the network name and can provide insights into network characteristics, potentially exposing network configurations or even sensitive network identifiers that might be used for further attacks. This design flaw falls under CWE-200, Information Exposure, and specifically relates to the improper exposure of sensitive information through system interfaces. The vulnerability represents a violation of the principle of least privilege as it unnecessarily exposes network information to all applications rather than restricting access to only those that require such information for legitimate functionality.
The operational impact of this vulnerability extends beyond simple information disclosure, creating potential pathways for more sophisticated attacks within the device ecosystem. An attacker could leverage this information to build detailed maps of wireless network environments, track device movement through signal strength variations, or identify specific network configurations that might be exploited in subsequent attacks. The lack of required user interaction or additional privileges makes this vulnerability particularly dangerous as it can be exploited silently in the background by any installed application. This type of information disclosure can enable adversaries to perform reconnaissance activities that would normally require more invasive techniques or physical access to the device. The vulnerability aligns with ATT&CK technique T1046, Network Service Scanning, and T1082, System Information Discovery, as it allows adversaries to gather information about network environments and device capabilities without direct user involvement or elevated privileges.
Mitigation strategies for this vulnerability focus on restricting the broadcast of sensitive wireless information through system intents and implementing more granular access controls for wireless network state information. The recommended approach involves modifying the Android framework to limit the information contained in wireless state change intents or to require specific permissions for accessing detailed network information. Application developers should implement proper input validation and avoid relying on potentially compromised information from system broadcasts. System administrators and device manufacturers should consider implementing network-level controls that limit the exposure of wireless information to applications that do not require such detailed network state information. The vulnerability highlights the importance of secure system design principles and the need for careful consideration of information flow within operating systems, particularly in areas where user privacy and security are paramount. Organizations should ensure that affected Android devices are updated to versions that address this vulnerability and implement monitoring to detect potential exploitation attempts through abnormal network state change activity.