CVE-2017-3749 in VIBE Mobile Phone
Summary
by MITRE
On Lenovo VIBE mobile phones, the Idea Friend Android application allows private data to be backed up and restored via Android Debug Bridge, which allows tampering leading to privilege escalation in conjunction with CVE-2017-3748 and CVE-2017-3750.
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Analysis
by VulDB Data Team • 10/21/2019
The vulnerability identified as CVE-2017-3749 represents a critical security flaw within Lenovo VIBE mobile devices that stems from improper implementation of Android backup mechanisms within the Idea Friend application. This issue specifically affects the Android Debug Bridge functionality that enables backup and restoration of private data, creating an attack surface that adversaries can exploit to gain elevated privileges on affected devices. The vulnerability operates at the system level where legitimate backup processes are leveraged to facilitate unauthorized data manipulation, fundamentally undermining the device's security model and user privacy protections.
The technical exploitation of CVE-2017-3749 relies on the Android Debug Bridge's capability to perform backup operations that bypass normal access controls and authentication mechanisms. When the Idea Friend application handles private data backup and restoration, it fails to implement proper cryptographic protection or authentication checks, allowing any local attacker with access to the device to manipulate backup files and subsequently restore them with elevated privileges. This flaw directly relates to CWE-312, which addresses the exposure of sensitive information through improper backup mechanisms, and demonstrates how backup functionality can become a vector for privilege escalation attacks when not properly secured.
The operational impact of this vulnerability extends beyond simple data exposure to encompass complete system compromise when combined with other related vulnerabilities in the same advisory. CVE-2017-3748 and CVE-2017-3750 create a multi-stage attack vector where an adversary can first exploit the backup mechanism through CVE-2017-3749, then leverage additional weaknesses to achieve full system control. This combination of vulnerabilities enables attackers to escalate privileges from standard user level to system-level access, potentially allowing complete device takeover and unauthorized access to all stored data including personal information, credentials, and sensitive communications. The attack requires local physical access to the device but can be executed without requiring additional authentication or network connectivity.
Mitigation strategies for CVE-2017-3749 must focus on both immediate device-level protections and long-term architectural improvements to prevent similar vulnerabilities. Users should disable Android Debug Bridge functionality when not actively required for development purposes, and manufacturers should implement proper cryptographic signing and verification mechanisms for all backup operations. The solution involves implementing proper access controls that prevent unauthorized modification of backup files, ensuring that backup restoration processes require authentication and that sensitive data is encrypted during backup operations. Organizations should also consider implementing mobile device management policies that restrict backup functionality on corporate devices and monitor for suspicious backup activities that may indicate exploitation attempts. This vulnerability highlights the importance of secure backup mechanisms and demonstrates how seemingly benign functionality can become a critical security risk when not properly implemented according to security best practices established in industry standards such as those defined by the National Institute of Standards and Technology and the Center for Internet Security.