CVE-2021-0677 in MT6833
Summary
by MITRE • 12/17/2021
In ccu driver, there is a possible out of bounds read due to an integer overflow. This could lead to local information disclosure with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: ALPS05827154; Issue ID: ALPS05827154.
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Analysis
by VulDB Data Team • 12/24/2021
The vulnerability identified as CVE-2021-0677 resides within the ccu driver component of a mobile operating system platform, specifically affecting Android-based devices. This issue represents a critical security flaw that manifests through an integer overflow condition during memory operations. The ccu driver serves as a crucial subsystem responsible for managing camera control unit functionalities and handling multimedia processing tasks within the device's hardware abstraction layer. The integer overflow occurs when processing certain data structures that exceed the maximum representable value for the designated integer type, leading to unexpected behavior in memory allocation and access patterns.
The technical implementation of this vulnerability involves a scenario where an attacker can manipulate input parameters to trigger an integer overflow during buffer size calculations. When the system processes camera-related data or multimedia commands, the ccu driver performs arithmetic operations on integer values that control memory allocation boundaries. The overflow condition causes the calculated buffer size to wrap around to a much smaller value than intended, resulting in an out-of-bounds read operation. This memory access violation occurs when the system attempts to read data beyond the allocated memory boundaries, potentially exposing sensitive information stored in adjacent memory locations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can potentially allow an attacker with system execution privileges to extract confidential data from memory regions that should remain protected. The flaw requires system-level execution privileges for exploitation, which typically means that an attacker would need to have already compromised the device's integrity or gained root access through other attack vectors. However, the lack of user interaction requirements makes this vulnerability particularly concerning as it can be exploited automatically without requiring any user engagement or specific actions. The information disclosure could potentially include cryptographic keys, authentication tokens, user credentials, or other sensitive data that resides in memory during normal operation of camera and multimedia functions.
From a cybersecurity perspective, this vulnerability aligns with CWE-190, which describes integer overflow and underflow conditions, and represents a classic example of how improper integer handling can lead to memory safety issues. The ATT&CK framework categorizes this vulnerability under privilege escalation techniques, specifically within the T1068 - Exploitation for Privilege Escalation tactic. The patch ID ALPS05827154 indicates that this issue was addressed through a platform-specific update that likely implemented proper integer overflow checking mechanisms and enhanced memory boundary validation within the ccu driver component. Organizations should prioritize applying this patch immediately, as the vulnerability could be leveraged in advanced persistent threat campaigns where attackers seek to extract sensitive information from compromised devices.
The broader implications of this vulnerability highlight the importance of robust input validation and memory safety practices in embedded systems and mobile operating environments. Given that the ccu driver operates at a low level within the system architecture, this flaw demonstrates how issues in hardware abstraction layers can create significant security risks. The vulnerability underscores the necessity of comprehensive code review processes that specifically target integer arithmetic operations, buffer management, and memory allocation routines. Security teams should implement monitoring protocols to detect anomalous memory access patterns and consider the potential for similar integer overflow conditions in other system drivers and components. The exploitation of such vulnerabilities typically requires sophisticated attack capabilities, but the potential for information disclosure makes it a critical concern for organizations managing mobile device fleets and IoT ecosystems where camera and multimedia functionalities are prevalent.