CVE-2018-21061 in Samsung
Summary
by MITRE
An issue was discovered on Samsung mobile devices with N(7.1) and O(8.x) software. A fake charger can execute critical functions in the locked state. The Samsung ID is SVE-2016-6341 (August 2018).
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Analysis
by VulDB Data Team • 10/07/2020
This vulnerability represents a critical security flaw in Samsung mobile devices running Android Nougat 7.1 and Oreo 8.x operating system versions. The issue stems from insufficient authentication mechanisms during the charging process, allowing malicious hardware to exploit a design weakness in the device's power management system. The vulnerability specifically affects devices where the charging interface can be manipulated to execute critical functions even when the device is locked, creating a significant attack surface that bypasses traditional security boundaries. This represents a fundamental flaw in the device's trust model, where the charging interface is not properly secured against unauthorized access.
The technical implementation of this vulnerability exploits the communication protocols between the device and charging hardware, particularly focusing on the power delivery negotiation process that occurs during charging. Attackers can create counterfeit chargers that, when connected to vulnerable Samsung devices, can establish unauthorized communication channels that trigger critical system functions. This exploitation occurs through manipulation of the charging protocol's authentication mechanisms, potentially allowing attackers to execute commands that should only be available to authorized users. The vulnerability operates at the hardware level, leveraging the device's charging interface to bypass the normal authentication and authorization processes that typically protect system functions.
The operational impact of this vulnerability is severe as it allows attackers to gain unauthorized access to critical device functions through a simple physical connection. An attacker with access to a counterfeit charger could potentially unlock the device, execute malicious code, or perform other unauthorized actions without requiring knowledge of the device's passcode or biometric authentication. This creates a persistent security risk that can be exploited in various real-world scenarios, including public charging stations, unattended device situations, or through supply chain attacks where malicious chargers are distributed to unsuspecting users. The vulnerability essentially transforms any charging port into a potential attack vector, significantly expanding the attack surface beyond traditional software-based threats.
Mitigation strategies for this vulnerability should focus on both hardware and software improvements to the device's charging interface security. Device manufacturers should implement stronger authentication mechanisms for charging protocols, ensuring that only authorized charging hardware can establish full communication with the device's core systems. The implementation should follow security standards such as those defined in CWE-284 Access Control and CWE-311 Missing Encryption of Sensitive Data, which address the specific weaknesses in authentication and communication security. Additionally, the vulnerability highlights the importance of supply chain security measures and user education regarding the risks of using unauthorized charging hardware. System-level mitigations should include enhanced monitoring of charging interface communications and implementation of device lock mechanisms that prevent critical function execution during unauthorized charging sessions. Organizations should also consider implementing the ATT&CK framework's T1547.001 Account Manipulation and T1566 Credential Access techniques to better understand and defend against potential exploitation pathways.