CVE-2026-28631 in Android
Summary
by MITRE • 09/08/2026
In buildMiniResolver of IntentForwarderActivity.java, there is a possible consent bypass due to a tapjacking/overlay attack. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.
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Analysis
by VulDB Data Team • 09/08/2026
The vulnerability identified in the buildMiniResolver method within IntentForwarderActivity.java represents a critical security flaw rooted in improper handling of user interface elements during intent resolution processes. This specific weakness allows an attacker to execute tapjacking or overlay attacks, which are techniques designed to deceive users by displaying fraudulent UI components over legitimate application interfaces. In this context, the vulnerability enables malicious applications to intercept and manipulate system-level prompts that require explicit user consent for sensitive operations. By exploiting this flaw, attackers can bypass critical security controls that rely on visual confirmation from the end-user, effectively tricking the operating system into granting permissions or executing actions without genuine user awareness or intent.
From a technical perspective, the core issue lies in how the application manages window flags and z-ordering of views during the creation of mini resolvers for intents. When an overlay is presented with higher priority than the consent dialog, it can capture touch events intended for the legitimate interface elements. This manipulation allows malicious code to simulate user interactions such as clicks on allow or grant buttons without any actual physical interaction from the device owner. The absence of required user interaction for exploitation significantly lowers the barrier for attack execution, allowing automated scripts or background processes to trigger privilege escalation vectors silently and efficiently.
The operational impact of this vulnerability is severe, particularly regarding local escalation of privilege. Since no additional execution privileges are needed beyond those already held by a malicious application installed on the device, even low-privilege apps can leverage this flaw to gain elevated access rights. This could result in unauthorized access to protected data, modification of system settings, or installation of further malware components with higher trust levels. The ability to bypass consent mechanisms undermines the fundamental security model of mobile operating systems which depend heavily on user-in-the-loop verification for sensitive permission grants.
This vulnerability aligns closely with CWE-829, Inclusion of Functionality from Untrusted Control Sector, as it involves accepting input or interaction that has been manipulated by an untrusted source through UI deception. Furthermore, the exploitation technique corresponds to ATT&CK Mobile Tactic TA0005 Defense Evasion and specifically maps to techniques involving overlay attacks designed to bypass security controls. The lack of proper window flag enforcement allows malicious overlays to obscure critical warning dialogs, thereby evading detection mechanisms that rely on visual cues or user acknowledgment.
Mitigation strategies must focus on enforcing strict UI hierarchy rules and preventing unauthorized overlay interactions. Developers should implement checks to ensure that sensitive consent dialogs are rendered in a way that prevents interception by lower-priority windows. Utilizing system-level protections such as FLAG_SECURE can help prevent screen capture but may not fully address tapjacking unless combined with proper window type configurations. Additionally, validating the source of touch events and ensuring that only legitimate user gestures trigger permission grants is essential. Regular security audits focusing on intent handling and UI rendering logic in critical pathways like IntentForwarderActivity are recommended to identify similar patterns before deployment.