CVE-2021-0348 in Android
Summary
by MITRE
In vpu, there is a possible out of bounds write due to a missing bounds check. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation. Product: Android; Versions: Android-9, Android-10, Android-11; Patch ID: ALPS05349201.
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Analysis
by VulDB Data Team • 02/24/2021
The vulnerability identified as CVE-2021-0348 resides within the vpu component of Android operating systems, representing a critical out-of-bounds write flaw that enables local privilege escalation. This issue affects Android versions 9, 10, and 11, indicating a widespread impact across multiple system generations. The vulnerability stems from the absence of proper bounds checking mechanisms within the vpu subsystem, which processes video and multimedia content. The flaw allows an attacker to write data beyond the allocated memory boundaries, potentially corrupting adjacent memory regions and executing arbitrary code with system-level privileges.
The technical nature of this vulnerability places it squarely within CWE-787, which describes out-of-bounds write conditions that occur when a program writes to memory locations outside the bounds of a buffer. This specific implementation flaw exists in the vpu component responsible for handling multimedia processing tasks, where insufficient input validation permits malicious data to overwrite critical system memory areas. The vulnerability requires system execution privileges for exploitation, meaning that an attacker must already have access to a system user account, though the ultimate outcome allows for complete system compromise through privilege escalation. This characteristic aligns with ATT&CK technique T1068, which covers local privilege escalation through the exploitation of system vulnerabilities.
The operational impact of CVE-2021-0348 extends beyond simple data corruption, as it creates a pathway for attackers to gain complete administrative control over affected devices. Once exploited, the vulnerability enables attackers to execute arbitrary code with the highest system privileges, effectively bypassing all standard security restrictions and access controls. This level of compromise allows for persistent access, data exfiltration, and further network infiltration. The lack of user interaction requirement for exploitation makes this vulnerability particularly dangerous as it can be triggered automatically without any user awareness or consent. The patch ID ALPS05349201 indicates that this vulnerability was addressed through a specific firmware update targeting the vpu subsystem, emphasizing the critical nature of the flaw.
Mitigation strategies for this vulnerability should focus on immediate system updates and patch management protocols. Organizations and users must prioritize applying the Android security patches released by Google and device manufacturers to prevent exploitation. Additionally, system administrators should implement monitoring for unusual memory access patterns and consider network segmentation to limit potential lateral movement if exploitation occurs. The vulnerability's classification as a local privilege escalation issue means that traditional network-based security measures may not prevent exploitation, requiring more comprehensive endpoint security solutions that can detect and prevent memory corruption attacks. Security teams should also conduct vulnerability assessments to identify any custom applications or services that might interact with the vpu subsystem and potentially introduce additional attack vectors.