CVE-2015-6621

Vulnerability

SystemUI in Android 5.x before 5.1.1 LMY48Z and Android 6.0 before the 2015-12-01 security patch level contains a privilege escalation vulnerability (internal bug 23909438). A crafted application can trigger this bug to obtain Signature or SignatureOrSystem level permissions, which are typically reserved for system or signed applications. [1]

Exploitation

An attacker must first install a crafted application on the target device. No additional authentication or user interaction beyond installation is required. The application then exploits the vulnerability in SystemUI to escalate its privileges, bypassing normal permission checks. [1]

Impact

Successful exploitation allows the attacker's application to gain Signature or SignatureOrSystem permissions. This enables the app to perform actions normally restricted to system-level components, such as accessing sensitive data or executing privileged operations, leading to a partial or complete compromise of the device's security. [1]

Mitigation

Google released fixes in Android 5.1.1 LMY48Z and Android 6.0 with the December 1, 2015 security patch level. Users should apply the OTA update or flash the updated firmware images from the Google Developer site. Partners were notified on November 2, 2015. No workarounds other than updating are provided. [1]