CVE-2025-20773: Android Display Use-After-Free Vulnerability

CVE-2025-20773 Overview

CVE-2025-20773 is a Use-After-Free (UAF) vulnerability discovered in the display driver component of MediaTek chipsets running Google Android. This memory corruption flaw exists in the display subsystem and could allow an attacker who has already obtained System-level privileges to escalate their access through local exploitation. The vulnerability requires no user interaction to exploit, making it particularly dangerous in targeted attack scenarios.

The vulnerability is tracked under MediaTek Patch ID ALPS10196993 and Issue ID MSV-4797. With a CVSS 3.1 score of 6.7 (Medium severity), the attack vector is local with low attack complexity, though it requires high privileges to exploit. The CVSS vector string is CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H, indicating high impact to confidentiality, integrity, and availability once exploited.

Critical Impact

An attacker with System privilege can exploit this Use-After-Free vulnerability to achieve local privilege escalation, potentially gaining full control over the affected Android device through memory corruption in the display driver.

Affected Products

• Google Android 14.0, 15.0, and 16.0
• MediaTek MT6700 series chipsets (MT6739, MT6761, MT6765, MT6768, MT6781, MT6789)
• MediaTek MT6800 series chipsets (MT6833, MT6835, MT6853, MT6855, MT6877, MT6878, MT6879, MT6883, MT6885, MT6886, MT6889, MT6893, MT6895, MT6897, MT6899)
• MediaTek MT6900 series chipsets (MT6983, MT6985, MT6989, MT6991)
• MediaTek MT8000 series chipsets (MT8196, MT8676, MT8678, MT8792, MT8793)
• MediaTek MT2718

Discovery Timeline

• December 2, 2025 - CVE-2025-20773 published to NVD
• December 3, 2025 - Last updated in NVD database

Technical Details for CVE-2025-20773

Vulnerability Analysis

This vulnerability is classified under CWE-416 (Use After Free) and CWE-415 (Double Free). The flaw resides in the display driver component of MediaTek chipsets, which is responsible for managing display memory buffers and rendering operations. Use-After-Free vulnerabilities occur when a program continues to use a pointer after the memory it references has been freed, leading to undefined behavior that can be exploited for arbitrary code execution or privilege escalation.

In this specific case, the display driver fails to properly manage memory lifecycle operations, allowing freed memory regions to be accessed or manipulated. The EPSS (Exploit Prediction Scoring System) indicates a probability of 0.005% with a percentile of 24.3%, suggesting relatively low likelihood of exploitation in the wild, though this may increase as technical details become more widely known.

Root Cause

The root cause of CVE-2025-20773 lies in improper memory management within the MediaTek display driver. When display-related memory objects are deallocated, references to these objects are not properly invalidated or nullified. This creates a dangling pointer scenario where subsequent code paths may attempt to access or manipulate the freed memory region.

The vulnerability specifically manifests in scenarios where display buffer management operations occur in rapid succession, creating a race condition-like window where freed memory can be accessed before proper cleanup is completed. This pattern is common in graphics drivers that handle complex memory allocation and deallocation cycles for display rendering.

Attack Vector

The attack vector for CVE-2025-20773 is local, requiring the attacker to already have System-level privileges on the target device. The exploitation flow involves:

1. An attacker with existing System privilege identifies the vulnerable code path in the display driver
2. The attacker triggers the memory allocation and deallocation sequence that creates the Use-After-Free condition
3. By carefully controlling the timing and contents of memory operations, the attacker can manipulate the freed memory region
4. The corrupted memory state is then used to escalate privileges beyond System level or execute arbitrary code in kernel context

Since no user interaction is required for exploitation, a malicious application or process running with System privileges could silently exploit this vulnerability. The high attack complexity noted in the CVSS metrics reflects the precision required in timing memory operations.

Detection Methods for CVE-2025-20773

Indicators of Compromise

• Unusual display driver crashes or system instability related to the display subsystem
• Unexpected privilege escalation attempts from processes with System-level access
• Abnormal memory allocation patterns in the display driver kernel module
• Suspicious activity in kernel logs related to display buffer management
• Kernel oops or panic messages referencing the MediaTek display driver components

Detection Strategies

Organizations should implement multi-layered detection approaches for this vulnerability:

Kernel-Level Monitoring: Deploy kernel-level security solutions capable of detecting Use-After-Free exploitation attempts. Modern Mobile Threat Defense (MTD) solutions can identify anomalous memory access patterns indicative of UAF exploitation.

System Integrity Monitoring: Implement continuous integrity checking for critical system processes. Any unexpected privilege escalation from System to higher privilege levels should trigger immediate alerts.

Behavioral Analysis: Utilize behavioral analysis tools to identify processes exhibiting exploitation patterns, such as rapid memory allocation/deallocation cycles followed by privilege escalation attempts.

Log Analysis: Monitor Android system logs and kernel debug output for display driver-related errors that may indicate exploitation attempts. Look for patterns involving memory corruption errors in the display subsystem.

Monitoring Recommendations

Security teams should establish baseline behavior for display driver operations on affected MediaTek devices and alert on deviations. Implement real-time monitoring for:

• Kernel memory allocation anomalies in display driver contexts
• Process privilege transitions that deviate from expected patterns
• Display driver error rates and crash frequencies
• Unexpected system calls from processes with System privilege

SentinelOne Singularity Mobile provides comprehensive protection against kernel-level exploitation attempts on Android devices, offering real-time detection of memory corruption attacks and privilege escalation techniques targeting MediaTek chipsets.

How to Mitigate CVE-2025-20773

Immediate Actions Required

• Apply the MediaTek security patch identified by Patch ID ALPS10196993 as soon as it becomes available through your device manufacturer
• Ensure Android devices are updated to the latest security patch level that includes the December 2025 MediaTek security bulletin fixes
• Audit system-level applications and services to minimize the attack surface for privilege escalation
• Implement additional access controls to limit which applications can obtain System privileges
• Deploy Mobile Threat Defense solutions capable of detecting kernel-level exploitation attempts

Patch Information

MediaTek has released security patches addressing this vulnerability as documented in their December 2025 Product Security Bulletin. The fix is tracked under Patch ID ALPS10196993. Device manufacturers and Android OEMs should integrate this patch into their firmware updates.

Users should obtain the patch through their device manufacturer's standard update channels. The patch addresses the memory lifecycle management issue in the display driver, ensuring proper invalidation of references when memory is freed.

For additional details, consult the vendor advisory at: https://corp.mediatek.com/product-security-bulletin/December-2025

Workarounds

Due to the nature of this kernel-level vulnerability in display driver firmware, there are no direct workarounds that can fully mitigate the risk without applying the official patch. However, organizations can implement compensating controls:

Reduce Attack Surface: Minimize the number of applications and services running with System-level privileges. Conduct regular audits of privileged processes and remove unnecessary elevated permissions.

Application Vetting: Implement strict application vetting processes to prevent installation of potentially malicious applications that could attempt privilege escalation.

Network Segmentation: Isolate vulnerable devices from critical network segments to limit the impact of potential compromise.

Device Management: Use Mobile Device Management (MDM) solutions to enforce security policies and monitor device health. Configure MDM to alert on any detected privilege escalation attempts.

# Android device security audit commands
# Check current security patch level
adb shell getprop ro.build.version.security_patch

# List privileged system applications
adb shell pm list packages -f | grep system

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