CVE-2018-21088 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with N(7.x) software. An attacker can cause a reboot because InputMethodManagerService has an unprotected system service. The Samsung ID is SVE-2017-9995 (January 2018).
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Analysis
by VulDB Data Team • 10/09/2020
The vulnerability identified as CVE-2018-21088 represents a critical security flaw in Samsung mobile devices running Android Nougat version 7.x software. This issue stems from improper protection of a system service within the InputMethodManagerService component, creating an exploitable condition that allows malicious actors to trigger unauthorized device reboots. The vulnerability was internally tracked by Samsung under the identifier SVE-2017-9995 and publicly disclosed in January 2018, highlighting the ongoing security challenges faced by mobile device manufacturers in protecting core system services from unauthorized access.
The technical root cause of this vulnerability lies in the lack of proper access controls within the InputMethodManagerService, which is responsible for managing input methods and text input functionality on Android devices. This system service should be protected from unauthorized access attempts, but in affected Samsung devices, the service lacks adequate security measures that would normally prevent malicious applications or attackers from invoking its functionality. The flaw essentially allows an attacker to send specially crafted requests to the InputMethodManagerService, which then triggers a system reboot without proper authentication or authorization checks. This represents a violation of the principle of least privilege and demonstrates poor implementation of Android's system service protection mechanisms.
The operational impact of this vulnerability extends beyond simple device disruption, as it provides attackers with a method to perform denial-of-service attacks against Samsung devices running affected software versions. The ability to remotely trigger device reboots can be particularly concerning in enterprise environments where device availability is critical, or in scenarios where attackers might use this capability as part of a broader exploitation campaign. The vulnerability could potentially be leveraged in combination with other exploits to create more sophisticated attack vectors, and it represents a significant weakening of the device's overall security posture. From a cyber threat perspective, this vulnerability could be exploited by malicious applications or remote attackers to disrupt device functionality and potentially gain further access to the system.
Security professionals should consider this vulnerability in the context of the Common Weakness Enumeration framework, where it aligns with CWE-284, which describes improper access control in system services, and CWE-310, which addresses cryptographic weakness in system components. The vulnerability also maps to several ATT&CK techniques including T1059 for command and script execution, and T1490 for denial of service attacks. Organizations should implement immediate mitigations including prompt software updates from Samsung, device enrollment in security management platforms that can detect and block suspicious service access patterns, and network monitoring for unusual reboot activity that might indicate exploitation attempts. Additionally, mobile device management solutions should enforce strict application permissions and monitor for unauthorized system service access that could indicate exploitation of this vulnerability.