CVE-2019-15432 in Evercoss
Summary
by MITRE
The Evercoss U6 Android device with a build fingerprint of EVERCOSS/U6/U6:7.0/NRD90M/1504236704:user/release-keys contains a pre-installed app with a package name of com.qiku.cleaner app (versionCode=2, versionName=2.0.0_VER_32516486284094) that allows other pre-installed apps to perform system properties modification via an accessible app component. This capability can be accessed by any pre-installed app on the device which can obtain signatureOrSystem permissions that are required by other other pre-installed apps that exported their capabilities to other pre-installed app.
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Analysis
by VulDB Data Team • 02/20/2024
The vulnerability identified as CVE-2019-15432 represents a critical security flaw within the Evercoss U6 Android device ecosystem, specifically targeting the device's permission model and system integrity mechanisms. This issue stems from a pre-installed application named com.qiku.cleaner which operates with elevated privileges and provides system modification capabilities to other pre-installed applications on the device. The vulnerability manifests through a design flaw in the Android permission system where the malicious app component exposes its functionality to other system applications that possess signatureOrSystem permissions, creating an unauthorized access vector for system property manipulation. The build fingerprint EVERCOSS/U6/U6:7.0/NRD90M/1504236704:user/release-keys indicates this vulnerability affects devices running Android 7.0 Nougat, a version that predates several security hardening measures implemented in later Android releases.
The technical exploitation of this vulnerability occurs through the improper exposure of system-level components within the Android framework, specifically targeting the system properties modification functionality. This flaw allows any pre-installed application that has been granted signatureOrSystem permissions to invoke the capabilities of the com.qiku.cleaner app, effectively bypassing normal Android security boundaries. The vulnerability can be categorized under CWE-276 as an Incorrect Permission Assignment, where the system component has been granted overly permissive access rights. From an operational perspective, this creates a dangerous privilege escalation scenario where legitimate system applications can manipulate core system properties without proper authorization, potentially enabling attackers to modify critical device parameters, alter security settings, or compromise the device's overall integrity. The vulnerability's impact is further amplified by the fact that it operates at the system level, making it particularly dangerous as it can affect device functionality and security mechanisms.
The operational implications of this vulnerability extend beyond simple privilege escalation to encompass potential device compromise and data exposure risks. Attackers who can gain access to pre-installed applications with signatureOrSystem permissions could potentially modify system properties to disable security features, alter device behavior, or establish persistent access points. This vulnerability aligns with several ATT&CK techniques including T1068 for Exploitation for Privilege Escalation and T1546 for Event Triggered Execution, as the malicious component can be triggered by legitimate system applications. The exposure of system modification capabilities through pre-installed applications represents a fundamental breach in Android's security model, where the principle of least privilege is violated. This allows for unauthorized modification of system properties such as device identifiers, security settings, or other critical parameters that could affect the device's security posture and operational integrity.
Mitigation strategies for CVE-2019-15432 should focus on immediate remediation through system updates and proper permission management. Device manufacturers should implement stricter permission controls for pre-installed applications, ensuring that only applications with legitimate system requirements receive signatureOrSystem permissions. The Android security model should be enhanced to prevent unauthorized component exposure between pre-installed applications, particularly those with system-level capabilities. Regular security audits should be conducted to identify and remove or restrict applications that expose unnecessary system functionality. From a defensive standpoint, organizations should implement mobile device management solutions that can monitor for unauthorized system property modifications and enforce strict application permission policies. Additionally, the vulnerability highlights the importance of proper application vetting processes for pre-installed software, ensuring that system components are not granted excessive privileges that could be exploited by malicious actors. The remediation process should include disabling or removing the vulnerable com.qiku.cleaner application when possible, and implementing runtime monitoring to detect unauthorized system property modifications that could indicate exploitation attempts.