CVE-2026-20489 in MT6991
Summary
by MITRE • 08/03/2026
In display, there is a possible information disclosure due to an integer overflow. This could lead to local information disclosure if a malicious actor has already obtained the System privilege. User interaction is not needed for exploitation. Patch ID: ALPS11004274; Issue ID: MSV-7749.
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Analysis
by VulDB Data Team • 08/03/2026
This vulnerability represents a critical information disclosure flaw within the display subsystem that stems from improper handling of integer overflow conditions. The vulnerability occurs when the system processes display-related operations that involve integer calculations, where an overflow condition can cause unexpected behavior in memory management or data handling routines. The flaw specifically manifests in scenarios where integer values exceed their maximum representable range, leading to wraparound behaviors that can be exploited to access unintended memory regions or data structures.
The technical implementation of this vulnerability aligns with common software security patterns where arithmetic operations lack proper bounds checking or overflow detection mechanisms. When an integer overflow occurs during display processing operations, the system may inadvertently expose sensitive information stored in adjacent memory locations or corrupt data structures that contain confidential metadata. This type of vulnerability typically falls under the category of CWE-190 - Integer Overflow or Wraparound, which is classified as a fundamental weakness in software design that can lead to various security consequences including information disclosure, privilege escalation, and system instability.
The operational impact of this vulnerability becomes particularly concerning when considering that exploitation requires only local system privileges, meaning that an attacker who has already compromised system-level access can leverage this flaw to extract additional sensitive information from the device. The absence of user interaction requirements makes this vulnerability especially dangerous as it can be exploited automatically without requiring any form of social engineering or user engagement. This characteristic places the vulnerability in the ATT&CK framework under the T1068 - Exploitation for Privilege Escalation technique, where attackers can use existing system-level access to gain further information disclosure capabilities.
The patch ID ALPS11004274 and issue ID MSV-7749 indicate that this vulnerability has been formally recognized and addressed by the vendor, suggesting that proper bounds checking mechanisms have been implemented to prevent integer overflow conditions in display processing operations. The mitigation strategy involves ensuring that all integer calculations within the display subsystem include proper overflow detection and handling procedures, which typically involves implementing checks before arithmetic operations or using language constructs that automatically detect and prevent such conditions. Organizations should prioritize applying this patch immediately as the vulnerability represents a direct threat to system confidentiality when combined with existing system-level access.
The broader implications of this vulnerability extend beyond simple information disclosure, as it demonstrates weaknesses in memory management and integer handling practices within critical system components. Such flaws often indicate that other similar vulnerabilities may exist within the same codebase or related subsystems, making comprehensive code review and security testing essential for organizations deploying affected systems. The vulnerability's classification as a local information disclosure also means that it could be combined with other attack vectors to create more sophisticated exploitation scenarios, though the current analysis focuses on its standalone capability when system privileges are already obtained.