CVE-2025-20749 is a stack overflow vulnerability classified under CWE-121, affecting numerous MediaTek System on Chips (SoCs) including MT6789, MT6835, MT6855, MT6878, MT6879, MT6886, MT6897, MT6899, MT6983, MT6985, MT6989, MT6991, MT8169, MT8188, MT8195, MT8196, MT8781, and MT8796. These SoCs are integrated into many Android devices running versions 14.0 through 16.0. The vulnerability exists in the charger component, where a missing bounds check allows an out-of-bounds write on the stack. This flaw can be exploited by a local attacker who already possesses System-level privileges to escalate their privileges further, potentially gaining higher control over the device. Notably, exploitation does not require user interaction, which increases the risk in environments where System privileges have been compromised or are accessible to malicious actors. The vulnerability was published on November 4, 2025, with no CVSS score assigned and no known exploits in the wild as of now. The lack of a patch link suggests that device manufacturers need to issue updates based on the MediaTek advisory (Patch ID: ALPS09915493; Issue ID: MSV-3800). The technical root cause is a classic stack-based buffer overflow due to improper input validation, which can lead to memory corruption and privilege escalation. Given the widespread use of MediaTek chipsets in consumer and enterprise mobile devices, this vulnerability poses a significant risk to device security and integrity.

For European organizations, this vulnerability could lead to serious security breaches if attackers gain System-level access on devices using affected MediaTek chipsets. The local privilege escalation can enable attackers to bypass security controls, install persistent malware, or exfiltrate sensitive data from mobile endpoints. This is particularly concerning for enterprises relying on mobile devices for secure communications, remote work, or critical infrastructure management. The absence of user interaction for exploitation means that compromised applications or malware already running with System privileges could leverage this flaw to deepen their control without alerting users. This could undermine device trustworthiness, lead to data breaches, and disrupt business operations. Furthermore, given the prevalence of MediaTek chipsets in mid-range and budget devices popular in Europe, a large number of endpoints could be vulnerable. The impact extends to mobile network operators and service providers who support these devices, potentially affecting the broader mobile ecosystem. The vulnerability also poses risks to privacy and regulatory compliance under frameworks such as GDPR if exploited to access personal or sensitive data.

To mitigate this vulnerability, European organizations should prioritize the following actions: 1) Work with device vendors and manufacturers to ensure timely deployment of patches addressing CVE-2025-20749. 2) Implement strict access controls to limit System-level privileges on mobile devices, ensuring only trusted applications and processes have such access. 3) Employ mobile device management (MDM) solutions to monitor and restrict installation of unauthorized software that could exploit this vulnerability. 4) Conduct regular security audits and vulnerability assessments on mobile endpoints to detect signs of compromise or privilege escalation attempts. 5) Educate users and administrators about the risks of privilege escalation and the importance of applying security updates promptly. 6) For organizations developing custom Android builds or firmware, incorporate bounds checking and secure coding practices to prevent similar vulnerabilities. 7) Monitor threat intelligence feeds for any emerging exploits targeting this vulnerability to respond swiftly. 8) Consider network segmentation and endpoint isolation strategies to contain potential breaches originating from compromised mobile devices.