CVE-2022-20107 in MT9011
Summary
by MITRE • 05/04/2022
In subtitle service, there is a possible application crash due to an integer overflow. This could lead to local denial of service with System execution privileges needed. User interaction is not needed for exploitation. Patch ID: DTV03330673; Issue ID: DTV03330673.
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Analysis
by VulDB Data Team • 05/07/2022
The vulnerability identified as CVE-2022-20107 resides within the subtitle service component of a digital television system, specifically manifesting as an integer overflow condition that can potentially cause application crashes. This flaw exists in the processing logic responsible for handling subtitle data within broadcast or streaming television environments, where the system encounters malformed or excessively large integer values during subtitle parsing operations. The vulnerability is particularly concerning as it operates at the system level where execution privileges are required, indicating that exploitation could lead to complete system compromise rather than mere denial of service. The integer overflow occurs when the system attempts to process subtitle data containing values that exceed the maximum capacity of the integer data type being used, causing the application to behave unpredictably and potentially crash.
The technical implementation of this vulnerability involves the subtitle service's failure to properly validate or sanitize integer inputs during the processing of subtitle metadata. When the system encounters subtitle data with malformed integer values, particularly those that exceed the maximum representable value for the target data type, the arithmetic operations involved in processing these values result in integer overflow conditions. This overflow can cause the application to allocate insufficient memory, trigger buffer overflows, or cause other memory corruption issues that ultimately lead to application instability and system crashes. The vulnerability demonstrates characteristics consistent with CWE-190, Integer Overflow or Wraparound, which is a well-documented class of vulnerabilities where integer arithmetic operations produce results that exceed the maximum value that can be represented by the data type. The lack of user interaction requirement for exploitation indicates that this vulnerability can be triggered automatically through legitimate subtitle data processing, making it particularly dangerous for automated systems.
The operational impact of CVE-2022-20107 extends beyond simple application crashes to potentially enable local denial of service attacks that could disrupt television broadcasting services or streaming platforms. In broadcast environments, this vulnerability could cause complete service interruptions when subtitle data is processed, affecting viewers who rely on subtitles for accessibility or language preferences. The requirement for system execution privileges suggests that exploitation could potentially allow attackers to escalate their control over the affected system, particularly in environments where subtitle services run with elevated privileges. This could lead to broader compromise of the television system, especially in integrated environments where subtitle processing is part of larger multimedia or content delivery systems. The vulnerability's presence in digital television systems aligns with ATT&CK technique T1499.004, Network Denial of Service, as it can cause service interruptions that affect availability of broadcast content.
Mitigation strategies for CVE-2022-20107 should focus on implementing proper input validation and integer overflow protection mechanisms within the subtitle service component. The most effective approach involves patching the system with the provided fix DTV03330673, which addresses the specific integer overflow condition in the subtitle processing logic. Organizations should implement comprehensive input sanitization procedures that validate all integer values before processing, including bounds checking and overflow detection mechanisms. Additionally, the system should employ proper error handling that prevents malformed subtitle data from causing application crashes, implementing graceful degradation rather than system failure. Security measures should include monitoring subtitle data processing for unusual integer values and implementing automated alerting systems when potential overflow conditions are detected. The vulnerability highlights the importance of robust integer handling in embedded systems and multimedia applications, particularly those operating in broadcast environments where reliability and availability are critical. Organizations should also consider implementing network segmentation and access controls to limit the potential impact of exploitation, ensuring that subtitle processing components operate with minimal required privileges to reduce the risk of privilege escalation attacks.