CVE-2021-0976 in Android
Summary
by MITRE • 12/15/2021
In toBARK of floor0.c, there is a possible out of bounds read due to a missing bounds check. This could lead to remote information disclosure with no additional execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-12Android ID: A-199680600
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Analysis
by VulDB Data Team • 12/18/2021
The vulnerability identified as CVE-2021-0976 resides within the toBARK component of floor0.c in Android 12 systems, representing a critical out-of-bounds read flaw that compromises system security. This issue manifests when the system fails to perform adequate bounds checking during memory access operations, creating a pathway for unauthorized data exposure. The vulnerability specifically affects the Android 12 operating system and is tracked under Android ID A-199680600, indicating its classification within Google's internal vulnerability tracking system. The flaw exists in the floor0.c file which likely handles memory management or data processing operations, making it a potential target for exploitation by malicious actors seeking to extract sensitive information from system memory.
The technical implementation of this vulnerability stems from the absence of proper input validation and boundary checks within the toBARK function or related memory handling code. When the system processes data through this component, it fails to verify that memory access operations remain within allocated boundaries, potentially allowing attackers to read memory locations beyond intended limits. This type of flaw falls under CWE-129, which specifically addresses "Improper Validation of Array Index," and represents a classic example of how insufficient bounds checking can lead to information disclosure vulnerabilities. The attack vector requires only a remote connection with no additional execution privileges, making it particularly dangerous as it can be exploited from external networks without requiring local system access or elevated permissions.
The operational impact of CVE-2021-0976 extends beyond simple information disclosure, as it can potentially expose sensitive system data, configuration parameters, or user information stored in memory regions that should remain protected. Attackers could leverage this vulnerability to extract cryptographic keys, authentication tokens, personal data, or other confidential information that resides in memory. The requirement for user interaction to initiate exploitation suggests that this vulnerability might be triggered through specific user actions such as opening malicious files, visiting compromised websites, or interacting with specially crafted content. This characteristic places the vulnerability in the ATT&CK framework under the technique T1059.001 for Command and Scripting Interpreter and potentially T1068 for Exploitation for Privilege Escalation, though the latter is mitigated by the lack of additional execution privileges required for exploitation.
Mitigation strategies for CVE-2021-0976 should focus on implementing comprehensive bounds checking mechanisms throughout the affected codebase, particularly within the floor0.c file and related memory management functions. Organizations should prioritize updating to patched Android 12 releases that address this specific vulnerability, as Google would have released security updates containing the necessary fixes. System administrators should also consider implementing network monitoring solutions to detect anomalous behavior that might indicate exploitation attempts, while applying the principle of least privilege to limit potential damage from successful attacks. The vulnerability demonstrates the critical importance of proper memory management practices and input validation, reinforcing industry best practices outlined in secure coding standards that emphasize the need for robust bounds checking mechanisms to prevent such information disclosure scenarios.