MediaTek Delivers Vital Security Fixes for Broad Chipset Range, Targeting High-Risk Exploits
MediaTek has rolled out a series of essential security updates aimed at neutralizing six major vulnerabilities discovered in its chipsets, which are used in an extensive variety of consumer electronics—from smartphones and tablets to smart TVs, AIoT devices, and audio systems.
The issues were detailed in MediaTek’s May 2025 Product Security Bulletin, which underscores the critical nature of the threats and their potential to affect millions of devices running Android and other platforms.
Major Threat: Remote Denial-of-Service Exploit (CVE-2025-20666)
Topping the list is CVE-2025-20666, a remote denial-of-service vulnerability stemming from a reachable assertion in the Modem subsystem (CWE-617). With a high-severity rating, this flaw allows attackers to crash affected devices remotely by exploiting an unhandled exception—no user action or elevated permissions required.
According to MediaTek, a compromised device could result simply from being within range of a rogue base station. This flaw affects over 30 MediaTek chipsets, including high-profile models like MT6833, MT6877, and MT6893, all utilizing Modem NR15 firmware.
What makes this vulnerability especially dangerous is its stealth—users may have no clue their device is under attack.
Additional Security Risks with Medium Severity
Alongside the critical DoS flaw, MediaTek addressed five medium-severity bugs, each posing distinct risks:
- CVE-2025-20667 – Weak Encryption in Modem Layer: A flaw in encryption implementation (CWE-326) could expose sensitive data if a device connects to an attacker-controlled base station. Affects chipsets using Modem LR12A, LR13, NR15–NR17R firmware.
- CVE-2025-20671 & CVE-2025-20668 – Memory Corruption via Out-of-Bounds Write: Located in the thermal and SCP components (CWE-787), these vulnerabilities may be exploited for local privilege escalation if attackers already have system-level access. Android 14 and 15 systems are particularly at risk.
- CVE-2025-20670 – Bypass Through Improper Certificate Validation: This issue (CWE-295) in the Modem stack could allow rogue base stations to bypass permissions and extract protected data.
- CVE-2025-20665 – Leakage of Device Identifiers: The devinfo component suffers from improper file/directory protections (CWE-538), potentially allowing local access to unique identifiers. This affects devices running Android 13 to 15.
What Users and OEMs Should Do
MediaTek has worked with hardware manufacturers under its coordinated disclosure policy, giving them advanced access to patch the vulnerabilities before public release. OEMs were notified at least two months prior to this announcement.
If your device is powered by a MediaTek chipset, it’s critical to check for and install the latest firmware or system updates issued by your device manufacturer. Delaying these updates could leave devices vulnerable to silent, remote exploitation.
Given the nature of CVE-2025-20666, even a passive device with no user interaction can be taken offline or compromised—making timely patching essential.
