Overview
CVE-2025-20755 describes a critical vulnerability affecting MediaTek modems. This vulnerability stems from improper input validation within the modem software, potentially leading to an application crash and a remote denial of service (DoS) condition. An attacker exploiting this flaw requires no user interaction and does not need elevated privileges on the device, making it particularly dangerous. Successful exploitation relies on the UE connecting to a rogue base station controlled by the attacker.
Technical Details
The root cause of CVE-2025-20755 is insufficient input validation within the modem software. When a User Equipment (UE) connects to a base station, data is exchanged, including parameters that the modem needs to process. The vulnerability lies in how the modem handles potentially malicious or malformed data received from a rogue base station. By sending crafted data, an attacker can trigger an application crash, resulting in a denial-of-service condition. The specific area of the modem software affected involves processing of data related to radio communication protocols. The Issue ID associated with this vulnerability is MSV-4775.
CVSS Analysis
The National Vulnerability Database (NVD) currently lists the severity and CVSS score as N/A. This is often the case when vulnerabilities are newly discovered or the complete analysis is still pending. However, based on the description, a high severity score is probable, given the remote, no-interaction, and no-privilege requirements for exploitation. A complete CVSS analysis will likely be available soon and reflected on the NVD website.
Possible Impact
The potential impact of CVE-2025-20755 is significant:
- Remote Denial of Service (DoS): Attackers can remotely crash the modem application, disrupting network connectivity for affected devices. This can affect smartphones, tablets, and other devices that rely on MediaTek modems for cellular communication.
- Widespread Disruption: If an attacker controls multiple rogue base stations, they could potentially launch a widespread DoS attack against numerous devices simultaneously.
- Battery Drain: Repeated crashes and restarts of the modem application can lead to increased battery consumption.
Mitigation and Patch Steps
The primary mitigation step is to apply the official security patch provided by MediaTek.
- Apply the Patch: Install the patch identified as MOLY00628396. This patch addresses the improper input validation issue and prevents the application crash. Contact your device manufacturer or check for system updates to obtain and install the patch.
- Be cautious about connecting to unknown networks: While not a primary defense, avoid connecting to untrusted or unknown cellular networks, as this could potentially expose your device to rogue base stations.
