CVE-2019-15343 in Camon iClick
Summary
by MITRE
The Tecno Camon iClick Android device with a build fingerprint of TECNO/H633/TECNO-IN6:8.1.0/O11019/A-180409V96:user/release-keys contains a pre-installed platform app with a package name of com.lovelyfont.defcontainer (versionCode=7, versionName=7.0.8). This app contains an exported service named com.lovelyfont.manager.FontCoverService that allows any app co-located on the device to supply arbitrary commands via shell script to be executed as the system user that are triggered by writing an attacker-selected message to the logcat log. This app cannot be disabled by the user and the attack can be performed by a zero-permission app. Executing commands as the system user can allow a third-party app to video record the user's screen, factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the Graphical User Interface (GUI), and obtains the user's text messages, and more. Executing commands as the system user can allow a third-party app to factory reset the device, obtain the user's notifications, read the logcat logs, inject events in the GUI, change the default Input Method Editor (IME) (e.g., keyboard) with one contained within the attacking app that contains keylogging functionality, and obtains the user's text messages, and more.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 02/14/2024
This vulnerability represents a critical privilege escalation flaw in the Tecno Camon iClick Android device that exploits a misconfigured system service to grant arbitrary command execution with system-level privileges. The vulnerability resides in the pre-installed platform application com.lovelyfont.defcontainer which contains an exported service named FontCoverService that can be invoked by any application on the device without requiring any special permissions. The attack vector leverages the logcat logging mechanism where an attacker can write a specially crafted message that triggers command execution through shell scripts. This represents a fundamental breakdown in Android's permission model and security boundaries, as the service operates outside the normal application sandbox restrictions that typically protect system-level operations.
The technical implementation of this vulnerability follows a well-documented pattern of privilege escalation through insecure service exposure, where the exported service acts as a command execution gateway that bypasses standard Android security controls. The system user context execution capability provides attackers with unprecedented access to device functions that are normally restricted to system-level applications. According to CWE-787, this vulnerability demonstrates an out-of-bounds write condition where the service accepts untrusted input from logcat messages and executes it directly without proper sanitization or validation. The attack can be initiated by any zero-permission application, making it particularly dangerous as it requires no user interaction or elevated privileges to exploit. This aligns with ATT&CK technique T1068 which describes the exploitation of legitimate system tools and services to gain system-level access.
The operational impact of this vulnerability is severe and encompasses a comprehensive set of malicious capabilities that can compromise user privacy and device integrity. Attackers can perform screen recording to capture sensitive information, execute factory resets that destroy user data, access notifications and text messages, read logcat logs to gather forensic information, inject GUI events to manipulate user interactions, and change the default input method editor to include keylogging functionality. These capabilities enable sophisticated surveillance attacks where users remain unaware of the compromise while their device becomes a tool for continuous monitoring and data exfiltration. The fact that this service cannot be disabled by users creates a persistent threat that remains active even after security updates or device reboots. The vulnerability affects all devices with the specified build fingerprint, creating a widespread exposure across affected hardware. The pre-installed nature of the application means that standard application management controls are ineffective, and the service operates with the highest privilege level available to applications, effectively granting attackers root-like capabilities for device manipulation.
Mitigation strategies must address both the immediate vulnerability and the underlying architectural issues that allowed this flaw to exist in the first place. Device manufacturers should implement proper service exposure controls and ensure that exported services undergo rigorous security review before deployment. Users should be advised to avoid installing untrusted applications that could exploit this vulnerability, though the zero-permission requirement makes this difficult to enforce. System administrators and security professionals should monitor for applications that attempt to interact with logcat services or execute shell commands, as these activities may indicate exploitation attempts. The vulnerability highlights the need for proper Android security hardening practices, including the removal of unnecessary exported services and implementation of proper input validation for all system-level components. Organizations should consider implementing device management policies that can disable or quarantine affected devices until proper patches are available, as this vulnerability represents a significant threat to enterprise security environments where device compromise could lead to broader network infiltration.