CVE-2021-25381 in Account
Summary
by MITRE • 04/10/2021
Using unsafe PendingIntent in Samsung Account in versions 10.8.0.4 in Android P(9.0) and below, and 12.1.1.3 in Android Q(10.0) and above allows local attackers to perform unauthorized action without permission via hijacking the PendingIntent.
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Analysis
by VulDB Data Team • 04/15/2021
The vulnerability CVE-2021-25381 represents a critical security flaw in Samsung Account applications across multiple android versions, specifically affecting Android P (9.0) and below with version 10.8.0.4 and Android Q (10.0) and above with version 12.1.1.3. This issue stems from the improper implementation of PendingIntent objects within the Samsung Account framework, creating a significant attack surface for local adversaries. The vulnerability manifests through the use of unsafe PendingIntent configurations that fail to properly validate or restrict the intent targets, allowing malicious applications to intercept and manipulate these pending operations. This particular flaw falls under the CWE-352 category of Cross-Site Request Forgery, specifically relating to improper validation of pending intent parameters and inadequate permission controls. The attack vector exploits the fundamental trust model of Android's intent system where PendingIntent objects are designed to execute actions on behalf of the application that created them, but in this case, the security boundaries are improperly enforced.
The technical exploitation of this vulnerability occurs when a malicious local application attempts to hijack the PendingIntent mechanism used by Samsung Account for various operations including account synchronization, authentication flows, and system integration tasks. When the Samsung Account application creates a PendingIntent without proper security configurations such as FLAG_IMMUTABLE or appropriate FLAG_NO_CREATE flags, it creates opportunities for attackers to manipulate the intent parameters or replace the original intent with their own malicious payload. This unsafe implementation allows the attacker to potentially redirect account operations, modify authentication flows, or execute unauthorized system actions that should only be accessible to the legitimate Samsung Account application. The vulnerability specifically impacts the Android permission model where the application should have enforced stricter controls over which components can access or modify these pending intents, creating a privilege escalation path through the improper handling of inter-process communication mechanisms.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it represents a complete breakdown in the application's security boundary enforcement and trust model. Local attackers can potentially perform account takeovers, modify account settings, access sensitive authentication tokens, or manipulate the synchronization state of Samsung services without proper authorization. The implications are particularly severe given that Samsung Account serves as a core integration point for various Samsung services including cloud synchronization, device management, and authentication flows that rely on the security of this component. This vulnerability enables attackers to perform actions that should require explicit user consent or system-level permissions, effectively bypassing the application's intended security controls. The attack surface is further expanded by the fact that the vulnerability affects multiple Android versions, suggesting a systemic issue in the Samsung Account implementation rather than a simple version-specific bug, which increases the potential for widespread exploitation.
Mitigation strategies for CVE-2021-25381 must address the fundamental security flaws in the PendingIntent implementation and enforce proper Android security boundaries. Organizations should implement immediate application updates that enforce proper PendingIntent flag usage including FLAG_IMMUTABLE for Android 7.0 and above, and ensure that all PendingIntent objects are created with appropriate security configurations to prevent external manipulation. The remediation should include code-level changes that validate intent parameters, enforce proper permission checks, and implement proper sandboxing of sensitive operations. Security controls should also include monitoring for unauthorized PendingIntent access patterns and implementing runtime integrity checks that verify the legitimacy of intent targets. From an ATT&CK perspective, this vulnerability maps to T1068 for privilege escalation and T1547 for persistence mechanisms, requiring defensive measures that monitor for suspicious intent manipulation and enforce proper application sandboxing. Organizations should also consider implementing application whitelisting controls and restricting the ability of third-party applications to access Samsung Account components through proper permission management and Android security model enforcement.