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This vulnerability exists in the `onUidImportance` callback method within `DisassociationProcessor.java` in the Android framework. The process for managing companion device applications involves associating and disassociating them from a host device, which grants and should revoke specific elevated privileges. When disassociation is triggered, the system is supposed to clear all privileged states and operations for the companion app’s Linux UID (user identifier). However, due to improper input validation in the importance handling logic, a race condition or specific sequence of events can cause the system to fail to fully clean up the UID’s state. This flaw allows the disassociated application’s process to retain some or all of its previous companion privileges. An attacker with local access can install and run a malicious companion app, pair it, then trigger the disassociation flaw. Because the system does not correctly validate and clear the UID’s privileged context, the malicious app continues to operate with escalated permissions it should no longer have, leading to local privilege escalation without requiring further execution capabilities, though user initiation of the disassociation is needed.
DailyCVE Form:
Platform: Android OS
Version: Android 15
Vulnerability: Privilege Escalation
Severity: High
date: 12/08/2025
Prediction: Early January 2026
What Undercode Say:
adb shell dumpsys activity services adb shell ps -A | grep 'companion' adb shell cmd device_config list
// Pseudo-code reflecting the flawed logic
void onUidImportance(int uid, int importance) {
if (isCompanionApp(uid) && importance == IMPORTANCE_FOREGROUND) {
// Grant/context logic
}
// Missing or incorrect validation during IMPORTANCE_ transitions post-disassociation
}
How Exploit:
1. Install malicious companion app.
2. User pairs device (association).
3. App gains privileges.
4. User triggers disassociation.
5. Flaw retains privileges post-disassociation.
6. App performs privileged actions.
Protection from this CVE
Apply Android security update. Disable unnecessary companion services. Strict input validation in UID lifecycle management.
Impact:
Local privilege escalation. Compromised device integrity. Bypass of sandbox restrictions.
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Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
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