CVE-2025-20772: Google Android Use-After-Free Vulnerability

CVE-2025-20772 Overview

CVE-2025-20772 is a use after free (UAF) memory corruption vulnerability discovered in the display driver component of MediaTek chipsets running on Google Android devices. This vulnerability exists in the display subsystem and could allow an attacker who has already obtained System-level privileges to escalate their access further through local exploitation. Notably, no user interaction is required for successful exploitation, making this vulnerability particularly concerning for compromised devices.

The vulnerability is classified as a Use After Free (CWE-416) and Double Free (CWE-415) issue, indicating that memory is accessed after it has been freed, or the same memory block is freed multiple times. These types of memory corruption vulnerabilities can lead to arbitrary code execution, system instability, or privilege escalation in the kernel or driver context.

Critical Impact

Local privilege escalation via memory corruption in the display driver allows attackers with System privileges to gain elevated access without user interaction across numerous MediaTek chipset-equipped Android devices.

Affected Products

• Google Android 14.0, 15.0, and 16.0
• MediaTek MT6739, MT6761, MT6765, MT6768, MT6781, MT6789 chipsets
• MediaTek MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879 chipsets
• MediaTek MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899 chipsets
• MediaTek MT6983, MT6985, MT6989, MT6991 chipsets
• MediaTek MT2718, MT8196, MT8676, MT8678, MT8792, MT8793 chipsets

Discovery Timeline

• 2025-12-02 - CVE-2025-20772 published to NVD
• 2025-12-03 - Last updated in NVD database

Technical Details for CVE-2025-20772

Vulnerability Analysis

CVE-2025-20772 is a memory corruption vulnerability in the display driver component of MediaTek chipsets. The vulnerability has been assigned a CVSS v3.1 score of 6.7 (MEDIUM) with the vector string CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H. This score reflects the local attack vector requiring high privileges but with low attack complexity and high impact on confidentiality, integrity, and availability.

The vulnerability is tracked internally by MediaTek as Patch ID: ALPS10196993 and Issue ID: MSV-4801. The EPSS (Exploit Prediction Scoring System) data indicates a probability of 0.005% with a percentile ranking of 24.3%, suggesting relatively low likelihood of exploitation in the wild.

Root Cause

The root cause of this vulnerability is improper memory management in the display driver, resulting in a use after free condition. When memory that has been deallocated is subsequently accessed or freed again (double free), it can lead to memory corruption. In the context of display drivers operating at kernel level, this type of vulnerability is particularly dangerous as it can corrupt kernel memory structures, potentially allowing an attacker to execute arbitrary code with elevated privileges.

The underlying weakness classifications include:

• CWE-416 (Use After Free): The display driver continues to reference memory after it has been freed, leading to undefined behavior when that memory is accessed or modified.
• CWE-415 (Double Free): The same memory block may be freed multiple times, corrupting memory management structures.

Attack Vector

The attack vector for CVE-2025-20772 is local (AV:L), meaning an attacker must have local access to the device to exploit this vulnerability. Critically, the attacker must have already obtained System-level privileges (PR:H) before attempting exploitation, which limits the attack surface but does not eliminate the risk.

Once System privileges are obtained (potentially through a separate vulnerability or malware infection), the attacker can trigger the use after free condition in the display driver without requiring any user interaction (UI:N). Successful exploitation could allow the attacker to:

1. Execute arbitrary code in kernel context
2. Further escalate privileges beyond System level
3. Compromise system integrity and confidentiality
4. Cause system instability or denial of service

The vulnerability affects the display subsystem's memory handling routines. When specific display operations are performed, the driver may access or free memory that has already been deallocated, creating an exploitable condition. For technical details on the specific vulnerable code paths, refer to the MediaTek Product Security Bulletin for December 2025.

Detection Methods for CVE-2025-20772

Indicators of Compromise

• Unexpected system crashes or reboots related to display driver operations
• Anomalous kernel memory allocation patterns or memory corruption errors in system logs
• Suspicious processes operating with elevated privileges interacting with display subsystem
• Evidence of privilege escalation from System to kernel-level access

Detection Strategies

Organizations should implement the following detection strategies to identify potential exploitation attempts:

Kernel Log Monitoring: Monitor kernel logs for display driver-related crashes, use after free errors, or memory corruption warnings. Look for references to display subsystem components, particularly around memory allocation and deallocation operations.

Behavioral Analysis: Deploy endpoint detection solutions capable of identifying anomalous behavior patterns, including:

• Unexpected privilege escalation sequences
• Unusual display driver API calls
• Memory access patterns indicative of exploitation

System Integrity Monitoring: Implement file integrity monitoring for system components and kernel modules. Changes to display driver components outside of authorized update windows should trigger alerts.

Monitoring Recommendations

1. Enable verbose logging for kernel and display driver components on high-value Android devices
2. Implement real-time monitoring for SEAndroid/SELinux policy violations related to display operations
3. Deploy mobile threat defense solutions with kernel-level visibility
4. Monitor for MediaTek-specific driver anomalies across the affected chipset families
5. Establish baseline behavior profiles for display driver operations to detect deviations

How to Mitigate CVE-2025-20772

Immediate Actions Required

• Apply the MediaTek security patch ALPS10196993 through OEM device updates immediately
• Ensure Android devices are running the latest security patch level from your device manufacturer
• Audit systems for signs of compromise, particularly devices that may have been exposed before patching
• Restrict physical and network access to potentially vulnerable devices until patches are applied
• Review and strengthen security controls that prevent initial System-level access compromise

Patch Information

MediaTek has released a security patch addressing this vulnerability as documented in their December 2025 Product Security Bulletin. The patch is identified as:

• Patch ID: ALPS10196993
• Issue ID: MSV-4801

Device manufacturers (OEMs) must integrate this patch into their Android builds and distribute it to end users. Users should check with their device manufacturer for the availability of security updates addressing CVE-2025-20772.

For detailed patch information, refer to the official MediaTek security advisory: https://corp.mediatek.com/product-security-bulletin/December-2025

Workarounds

Due to the nature of this vulnerability (kernel-level memory corruption in a hardware driver), there are limited workarounds available without applying the official patch. However, organizations can implement the following risk reduction measures:

1. Minimize Attack Surface: Since exploitation requires existing System-level privileges, focus on preventing initial compromise through:

   • Enforcing strong device security policies
   • Disabling unnecessary services and applications
   • Implementing mobile device management (MDM) solutions

2. Network Segmentation: Isolate potentially vulnerable devices from critical network resources until patches are applied

3. Enhanced Monitoring: Implement heightened monitoring for affected devices to detect exploitation attempts early

4. Application Allowlisting: Restrict installation of applications to trusted sources to reduce the risk of initial compromise that could lead to System privilege acquisition

# Check Android security patch level on device
adb shell getprop ro.build.version.security_patch

# Monitor kernel logs for display driver anomalies
adb logcat -b kernel | grep -i "display\|drm\|mtk"