CVE-2025-20798 is an out-of-bounds write vulnerability classified under CWE-787 affecting a wide range of MediaTek System on Chips (SoCs), including MT2718, MT6765, MT6768, MT6781, MT6833, MT6835, MT6853, MT6855, MT6877, MT6879, MT6893, MT6985, MT6989, MT6991, MT8186, MT8188, MT8196, MT8367, MT8391, MT8676, MT8678, MT8696, MT8766, MT8768, MT8781, MT8786, MT8788E, MT8791T, MT8792, MT8793, MT8796, MT8873, MT8883, and MT8893. These chipsets are integrated into numerous Android devices running Android versions 14.0 through 16.0. The vulnerability arises from a missing bounds check in the battery component, which allows an attacker who already has System-level privileges on the device to perform an out-of-bounds write. This memory corruption can lead to local escalation of privilege, potentially enabling the attacker to gain higher privileges or execute arbitrary code with elevated rights. Notably, exploitation does not require user interaction, increasing the risk of automated or stealthy attacks. The CVSS v3.1 base score is 7.8, reflecting high impact on confidentiality, integrity, and availability, with low attack complexity and requiring only low privileges. Although no public exploits are currently known, the vulnerability is critical due to the widespread deployment of affected MediaTek SoCs in consumer and enterprise Android devices. The issue was reserved in November 2024 and published in January 2026, with a patch identified as ALPS10315812. The vulnerability underscores the importance of rigorous input validation and bounds checking in embedded firmware components, especially those managing critical hardware functions like battery management.

The vulnerability allows a local attacker with System privileges to escalate their privileges further, potentially gaining root or kernel-level access. This can lead to complete compromise of the device, including unauthorized access to sensitive data, installation of persistent malware, disruption of device functionality, or denial of service. Since the affected chipsets are widely used in Android smartphones and IoT devices globally, the impact extends to millions of devices. Organizations relying on MediaTek-based devices for mobile workforce or IoT deployments could face data breaches, operational disruptions, and increased risk of espionage or sabotage. The lack of user interaction requirement facilitates stealthy exploitation, increasing the threat to high-value targets. The vulnerability also poses risks to supply chain security, as compromised devices could be used to pivot attacks into corporate networks. The broad range of affected chipsets and Android versions increases the scope and scale of potential impact.

1. Apply the official patch ALPS10315812 from MediaTek or device manufacturers as soon as it becomes available to ensure the bounds check is correctly implemented. 2. Enforce strict privilege separation on devices to limit the ability of processes with System privileges to escalate further. 3. Employ runtime memory protection mechanisms such as Address Space Layout Randomization (ASLR) and Control Flow Integrity (CFI) to mitigate exploitation of memory corruption vulnerabilities. 4. Monitor device logs and behavior for anomalies indicative of privilege escalation attempts, especially on devices running affected MediaTek chipsets. 5. Restrict installation of untrusted applications and enforce application whitelisting to reduce the risk of initial compromise leading to System privileges. 6. For enterprises, consider network segmentation and endpoint detection solutions tailored for mobile devices to detect lateral movement or exploitation attempts. 7. Collaborate with device vendors to ensure timely firmware updates and verify patch deployment across device fleets. 8. Educate users and administrators about the risks of privilege escalation vulnerabilities and the importance of applying updates promptly.