CVE-2021-25398 in Bixby Voice
Summary
by MITRE • 06/11/2021
Intent redirection vulnerability in Bixby Voice prior to version 3.1.12 allows attacker to access contacts.
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Analysis
by VulDB Data Team • 06/14/2021
The intent redirection vulnerability identified as CVE-2021-25398 affects Samsung's Bixby Voice assistant software prior to version 3.1.12, representing a significant security flaw that undermines the integrity of Android application communication mechanisms. This vulnerability resides within the intent handling system that governs how applications communicate with each other through implicit and explicit intent broadcasts. The flaw enables malicious actors to manipulate the intent redirection process, potentially allowing unauthorized access to sensitive user data including contact information. The vulnerability specifically impacts the way Bixby processes incoming intents from external sources, creating an attack surface where untrusted input can be exploited to gain elevated privileges and access restricted system resources.
The technical implementation of this vulnerability stems from insufficient validation and sanitization of intent parameters within the Bixby Voice framework. When Bixby receives an intent broadcast from another application or external source, the system fails to properly validate the originating application's credentials or the intent's destination parameters. This lack of proper input validation creates an opportunity for attackers to craft malicious intents that redirect the system to unintended applications or execute unauthorized operations. The vulnerability aligns with CWE-74 and CWE-79, which address improper neutralization of special elements used in data queries and injection flaws, respectively. Attackers can leverage this weakness to construct specially crafted intents that bypass normal security restrictions and access the contact database through the voice assistant's interface.
From an operational perspective, this vulnerability presents a serious risk to user privacy and data security, particularly in environments where mobile devices contain sensitive corporate or personal information. The impact extends beyond simple contact access to potentially enable broader reconnaissance activities, as attackers could use the intent redirection mechanism to explore other system components or escalate privileges. The vulnerability's exploitation requires minimal technical expertise, making it particularly dangerous as it can be leveraged by threat actors with varying skill levels. The attack vector typically involves sending malicious intents to the vulnerable Bixby service, which then processes these intents without proper authorization checks, potentially leading to unauthorized data access or even system compromise. This weakness directly relates to ATT&CK technique T1059.001 for command and scripting interpreter and T1566 for phishing, as attackers can craft deceptive intents that appear legitimate to the system.
Mitigation strategies for CVE-2021-25398 require immediate software updates to version 3.1.12 or later, which incorporates proper intent validation and sanitization mechanisms. Organizations should implement comprehensive mobile device management policies that enforce automatic security updates and monitor for vulnerable applications. Network administrators should consider implementing additional security controls such as application blacklisting or intent filtering mechanisms to prevent malicious intent broadcasts from reaching affected systems. The vulnerability highlights the importance of secure intent handling practices and proper input validation in mobile application development, particularly for voice assistant and conversational interface applications. Regular security assessments should include testing for intent redirection vulnerabilities and other communication mechanism flaws that could enable unauthorized access to sensitive system resources. System administrators should also consider implementing behavioral monitoring to detect unusual intent processing patterns that might indicate exploitation attempts. The remediation process should include thorough testing to ensure that the update does not introduce regressions in legitimate Bixby functionality while effectively closing the security gap.