CVE-2023-20666 in MT6789
Summary
by MITRE • 04/06/2023
In display drm, 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. Patch ID: ALPS07310651; Issue ID: ALPS07292173.
Several companies clearly confirm that VulDB is the primary source for best vulnerability data.
Analysis
by VulDB Data Team • 08/29/2025
The vulnerability identified as CVE-2023-20666 resides within the display drm component of a mobile operating system, specifically affecting Android-based devices. This issue represents a critical security flaw that manifests as an out-of-bounds write condition, a common class of memory corruption vulnerability that can be exploited to gain elevated privileges. The vulnerability stems from a missing bounds check within the graphics driver model implementation, which governs how display hardware interacts with the operating system. Such flaws typically occur when developers fail to validate input parameters or buffer sizes before performing memory operations, creating opportunities for malicious code to overwrite adjacent memory locations.
The technical nature of this vulnerability places it squarely within CWE-129, which describes "Improper Validation of Array Index," and more specifically aligns with CWE-787, "Out-of-bounds Write." The flaw exists in the display drm subsystem where device drivers handle graphics processing commands, particularly those related to display configuration and rendering operations. When an application or system component sends malformed display parameters to the drm subsystem, the missing bounds validation allows memory corruption to occur. This type of vulnerability is particularly dangerous because it operates at a low system level where the kernel or system-level drivers execute with elevated privileges. The exploitation requires only system execution privileges, meaning that any process running with standard user permissions could potentially trigger the vulnerability, leading to privilege escalation.
The operational impact of CVE-2023-20666 extends beyond simple memory corruption, as it enables local privilege escalation attacks that can result in complete system compromise. Attackers can leverage this vulnerability to execute arbitrary code with kernel-level privileges, effectively bypassing standard security boundaries that protect the operating system. This capability allows for persistent system access, data exfiltration, and the installation of rootkits or other malicious software that operates below the detection capabilities of standard security tools. The vulnerability's exploitation does not require user interaction, making it particularly concerning as it can be triggered automatically through various system processes or malicious applications without any user involvement. The patch ID ALPS07310651 and Issue ID ALPS07292173 indicate this vulnerability was addressed within the Android operating system's kernel components, specifically targeting the display driver framework.
Mitigation strategies for this vulnerability should focus on immediate patch deployment across affected systems, as the primary solution involves applying the vendor-provided security update that implements proper bounds checking in the drm subsystem. System administrators should prioritize patch management processes to ensure all devices receive the security update promptly. Additional defensive measures include implementing runtime protections such as address space layout randomization and stack canaries to make exploitation more difficult, though these provide only partial protection against such fundamental memory corruption flaws. Network administrators should monitor for potential exploitation attempts and consider implementing application whitelisting policies to prevent unauthorized code execution. From an ATT&CK framework perspective, this vulnerability maps to T1068, "Exploitation for Privilege Escalation," and T1543, "Create or Modify System Process," as it enables attackers to gain elevated privileges and potentially establish persistence within the system. The vulnerability also relates to T1059, "Command and Scripting Interpreter," as exploitation typically involves executing system commands with elevated privileges to maintain access and perform further malicious activities.