CVE-2025-20723 is a vulnerability classified under CWE-787 (Out-of-bounds Write) found in the GNSS (Global Navigation Satellite System) driver of multiple MediaTek chipsets, including MT6835, MT6878, MT6886, MT6897, MT6899, MT6985, MT6989, MT6991, MT8676, MT8678, MT8775, MT8791T, MT8796, and MT8873. These chipsets are integrated into various Android devices running versions 14.0 and 15.0. The vulnerability stems from an incorrect bounds check in the GNSS driver code, which can lead to writing data outside the intended memory boundaries. This out-of-bounds write can corrupt memory, potentially allowing an attacker who already has System-level privileges on the device to escalate their privileges further, possibly gaining higher-level kernel privileges or executing arbitrary code. Exploitation does not require user interaction, meaning that once an attacker has local System access, they can exploit this vulnerability without additional user actions. The flaw does not appear to be remotely exploitable and requires local access at the System privilege level, which limits the initial attack vector but increases the risk of post-compromise escalation. No known public exploits or active exploitation have been reported as of the publication date. The vendor has assigned a patch ID (ALPS09920033) and an internal issue ID (MSV-3797), indicating that a fix is planned or available. The vulnerability affects a broad range of MediaTek SoCs, which are widely used in mid-range and some high-end mobile devices globally. The lack of a CVSS score necessitates an independent severity assessment based on the impact and exploitability factors.

For European organizations, the primary impact of CVE-2025-20723 lies in the potential for local privilege escalation on devices using affected MediaTek chipsets. This could compromise the confidentiality, integrity, and availability of sensitive data on mobile devices, especially those used in corporate environments or critical infrastructure sectors. Attackers who gain System-level access—via other vulnerabilities, malware, or insider threats—could leverage this flaw to gain deeper control over the device, bypass security controls, or persist undetected. This is particularly concerning for sectors relying heavily on mobile communications and location services, such as logistics, transportation, emergency services, and government agencies. The vulnerability could also affect the stability and reliability of devices, potentially causing crashes or erratic behavior. Given the widespread use of MediaTek chipsets in consumer and enterprise mobile devices across Europe, the risk extends to a large user base. However, the requirement for local System privileges limits the likelihood of remote exploitation, reducing the immediate threat to large-scale network compromise. Nonetheless, targeted attacks against high-value individuals or organizations remain plausible. The absence of known exploits in the wild provides a window for proactive mitigation before active exploitation occurs.

1. Apply vendor patches promptly: Monitor MediaTek and device manufacturers for the release of security updates addressing CVE-2025-20723 and deploy them as soon as they become available. 2. Restrict local System-level access: Enforce strict access controls on devices to limit System privilege usage to trusted administrators and processes only. 3. Harden device security: Utilize mobile device management (MDM) solutions to enforce security policies, including disabling unnecessary services and restricting installation of untrusted applications. 4. Monitor for suspicious activity: Implement endpoint detection and response (EDR) tools capable of identifying unusual privilege escalation attempts or memory corruption indicators on affected devices. 5. Educate users and administrators: Raise awareness about the risks of privilege escalation vulnerabilities and the importance of maintaining updated software. 6. Network segmentation: Isolate critical devices and sensitive data environments to reduce the impact of a compromised device. 7. Conduct regular security audits: Periodically review device configurations and access logs to detect potential misuse of System privileges. 8. Limit exposure: Where feasible, avoid deploying devices with affected MediaTek chipsets in high-risk or sensitive operational environments until patched.