CVE-2025-20769 Overview
CVE-2025-20769 is an out-of-bounds write vulnerability affecting the display driver component in Android devices running on MediaTek chipsets. The vulnerability exists due to a missing bounds check in the display subsystem, which could allow a local attacker who has already obtained System privilege to escalate their access further. This vulnerability requires no user interaction for exploitation, making it particularly concerning in scenarios where an attacker has already achieved initial compromise of a device.
The vulnerability is classified as CWE-787 (Out-of-bounds Write) and CWE-121 (Stack-based Buffer Overflow), indicating the underlying memory safety issue in the display driver code. With a CVSS score of 6.7 (Medium severity), this vulnerability presents significant risk in attack chains where privilege escalation is needed.
Critical Impact
Local privilege escalation from System to higher privileges possible without user interaction on affected MediaTek-based Android devices.
Affected Products
- Google Android 14.0, 15.0, 16.0
- MediaTek MT6739, MT6761, MT6765, MT6768, MT6781, MT6789
- MediaTek MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879
- MediaTek MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899
- MediaTek MT6983, MT6985, MT6989, MT6991
- MediaTek MT2718, MT8196, MT8676, MT8678, MT8792, MT8793
Discovery Timeline
- 2025-12-02 - CVE-2025-20769 published to NVD
- 2025-12-03 - Last updated in NVD database
Technical Details for CVE-2025-20769
Vulnerability Analysis
The vulnerability resides in the display driver subsystem of Android devices utilizing MediaTek system-on-chip (SoC) components. The flaw is characterized by a missing bounds check that enables an out-of-bounds write operation. According to the CVSS vector (CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H), the vulnerability:
- Requires local access to the device
- Has low attack complexity once prerequisites are met
- Requires high privileges (System-level access) as a prerequisite
- Requires no user interaction
- Can result in high confidentiality, integrity, and availability impact
The vulnerability affects a broad range of MediaTek chipsets spanning entry-level to flagship processors, including the MT67xx series (mobile), MT68xx series (premium mobile), and MT8xxx series (tablet/IoT platforms).
Root Cause
The root cause of CVE-2025-20769 is a missing bounds check in the display driver component. When processing display-related operations, the driver fails to properly validate the size or index of data being written, allowing writes to occur outside the intended memory buffer boundaries. This is a classic memory safety vulnerability pattern that can lead to stack-based buffer overflow conditions (CWE-121) resulting in out-of-bounds write operations (CWE-787).
The absence of proper boundary validation means that specially crafted input or operations can cause the driver to write data beyond allocated memory regions, potentially corrupting adjacent memory structures, function pointers, or other security-critical data.
Attack Vector
The attack vector is local, meaning an attacker must have existing access to the target device. The prerequisite of System privilege indicates this vulnerability is most useful as part of an exploit chain where an attacker has already achieved initial compromise through another vulnerability or through a malicious application with elevated permissions.
Once System-level access is obtained, an attacker could trigger the display driver vulnerability to write controlled data outside intended memory boundaries. This could be leveraged to:
- Corrupt kernel data structures
- Overwrite function pointers to redirect execution flow
- Escalate from System privilege to kernel-level access
- Achieve persistence on the device
The vulnerability does not require any user interaction, making automated exploitation feasible once the prerequisites are met.
Detection Methods for CVE-2025-20769
Indicators of Compromise
- Unexpected crashes or instability in the display subsystem or system UI
- Anomalous system calls to display driver interfaces from processes with System privileges
- Evidence of privilege escalation attempts following System-level compromise
- Unusual memory access patterns in kernel logs related to display operations
- Signs of exploit chain activity targeting Android system services
Detection Strategies
Kernel Audit Logging: Enable comprehensive kernel audit logging to monitor for suspicious ioctl calls and memory operations targeting display driver interfaces. Look for patterns indicating boundary violations or attempts to access restricted kernel memory regions.
Mobile Device Management (MDM): Deploy MDM solutions that can monitor for signs of device compromise, including unexpected privilege changes, system partition modifications, or unauthorized kernel module loading.
Runtime Application Self-Protection (RASP): Implement RASP solutions on managed devices to detect and block exploitation attempts in real-time by monitoring application behavior and system interactions.
Security Information and Event Management (SIEM): Correlate device logs with SIEM platforms to identify patterns indicative of exploit chains that may leverage this vulnerability.
Monitoring Recommendations
Organizations should implement continuous monitoring for Android devices in their fleet, particularly those utilizing MediaTek chipsets. Key monitoring activities include:
- Regular integrity checks of system partitions and kernel components
- Monitoring for abnormal battery drain or performance degradation that may indicate background exploit activity
- Tracking security patch levels across the device fleet to identify vulnerable devices
- Implementing network-level monitoring for post-exploitation command and control communications
How to Mitigate CVE-2025-20769
Immediate Actions Required
- Apply the MediaTek security patch ALPS10196993 when available from device manufacturers
- Prioritize patching for devices in high-risk environments or those with access to sensitive data
- Implement additional access controls to limit applications that can obtain System privileges
- Enable SELinux in enforcing mode to provide defense-in-depth against exploitation
- Review and restrict applications with elevated permissions that could be used as stepping stones
Patch Information
MediaTek has addressed this vulnerability in their December 2025 Product Security Bulletin under Patch ID ALPS10196993 (Issue ID: MSV-4804). Device manufacturers and OEMs using affected MediaTek chipsets should integrate this patch into their Android security updates.
The patch adds proper bounds checking to the display driver component, preventing out-of-bounds write operations. End users should apply Android security updates as soon as they become available from their device manufacturer or carrier.
EPSS Score: The Exploit Prediction Scoring System (EPSS) indicates a 0.004% probability of exploitation, placing this vulnerability in the 15.5th percentile. While the exploitation probability is relatively low, the potential impact of successful exploitation warrants prompt patching.
For official patch information and technical details, refer to the MediaTek Product Security Bulletin - December 2025.
Workarounds
If immediate patching is not possible, organizations should implement the following temporary mitigations:
Restrict Application Permissions: Audit and restrict applications that have or can request System-level permissions. Limit the attack surface by removing unnecessary privileged applications.
Enable Verified Boot: Ensure that Android Verified Boot is enabled to detect unauthorized modifications to the system partition that could indicate exploitation.
Network Segmentation: Isolate vulnerable devices on restricted network segments to limit the impact of potential compromise.
User Awareness: Educate users about the risks of sideloading applications or granting excessive permissions to untrusted software.
# Check device security patch level
adb shell getprop ro.build.version.security_patch
# Verify SELinux is enforcing
adb shell getenforce
# List applications with system-level permissions
adb shell pm list packages -f | grep system
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
