CVE-2025-59439 Overview
A denial of service vulnerability has been identified in Samsung Exynos mobile processors, wearable processors, and modems. The vulnerability stems from incorrect handling of NAS (Non-Access Stratum) Registration messages, which leads to improper handling of exceptional conditions. An attacker can exploit this flaw remotely over the network without requiring authentication or user interaction, resulting in a complete denial of service condition affecting device availability.
Critical Impact
Remote attackers can cause denial of service on Samsung Exynos-based devices by sending malformed NAS Registration messages, potentially disrupting cellular connectivity and device functionality.
Affected Products
- Samsung Exynos 980 Mobile Processor and Firmware
- Samsung Exynos 990 Mobile Processor and Firmware
- Samsung Exynos 850 Mobile Processor and Firmware
- Samsung Exynos 1080 Mobile Processor and Firmware
- Samsung Exynos 9110 Wearable Processor and Firmware
- Samsung Exynos W920 Wearable Processor and Firmware
- Samsung Exynos W930 Wearable Processor and Firmware
- Samsung Exynos W1000 Wearable Processor and Firmware
- Samsung Exynos Modem 5123 and Firmware
Discovery Timeline
- 2026-02-03 - CVE-2025-59439 published to NVD
- 2026-02-05 - Last updated in NVD database
Technical Details for CVE-2025-59439
Vulnerability Analysis
This vulnerability affects the baseband modem component of Samsung Exynos processors, specifically in how NAS Registration messages are processed. NAS (Non-Access Stratum) is a functional layer in cellular network protocols responsible for managing signaling between user equipment (UE) and the core network for mobility management and session management.
The flaw exists because the affected processors fail to properly handle exceptional conditions when parsing NAS Registration messages. When a malformed or unexpected NAS message is received, the processor does not gracefully handle the error condition, leading to resource exhaustion or a crash state that results in denial of service.
The vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the improper exception handling allows an attacker to consume system resources or trigger a failure state that prevents normal device operation.
Root Cause
The root cause is improper handling of exceptional conditions (CWE-400) within the NAS Registration message parsing logic in the Exynos baseband firmware. When the modem receives a specially crafted NAS Registration message containing unexpected or malformed data, the exception handling mechanism fails to properly manage the error state. This can result in the modem entering an unrecoverable state, consuming excessive resources, or crashing entirely.
Attack Vector
The attack can be executed remotely over the network without requiring any privileges or user interaction. An attacker with the ability to send cellular signaling messages to a target device can exploit this vulnerability. This could potentially be achieved through:
- A rogue base station (fake cell tower) that sends malicious NAS Registration messages to devices within range
- Man-in-the-middle attacks on cellular communications
- Compromised network infrastructure that can inject malformed NAS messages
The attack does not require authentication and affects device availability without impacting confidentiality or integrity. Once exploited, the affected device may lose cellular connectivity or require a restart to recover normal operation.
Detection Methods for CVE-2025-59439
Indicators of Compromise
- Unexpected device reboots or modem crashes coinciding with cellular network activity
- Loss of cellular connectivity without apparent network issues
- Repeated modem subsystem restarts visible in device logs
- Unusual patterns of NAS Registration message failures in network logs
Detection Strategies
- Monitor device health telemetry for abnormal modem restart patterns
- Implement network-level monitoring for malformed NAS signaling messages
- Deploy endpoint detection solutions capable of monitoring baseband activity
- Review cellular network logs for suspicious registration message patterns from specific cell sites
Monitoring Recommendations
- Enable verbose logging on affected devices to capture modem subsystem events
- Implement alerting for repeated cellular connectivity failures across device fleets
- Monitor for rogue base station activity in your operational environment
- Coordinate with mobile network operators to identify anomalous signaling traffic
How to Mitigate CVE-2025-59439
Immediate Actions Required
- Review the Samsung Security Advisory for patch availability
- Inventory all devices using affected Exynos processors in your environment
- Prioritize firmware updates for devices with higher exposure risk
- Consider limiting exposure to untrusted cellular networks where possible
Patch Information
Samsung has released security updates addressing this vulnerability. Organizations should apply the latest firmware updates for affected Exynos processors as soon as they become available through device manufacturers. Detailed patch information is available at the Samsung Product Security Updates page.
For devices running Exynos 980, Exynos 990, Exynos 850, Exynos 1080, Exynos 9110, Exynos W920, Exynos W930, Exynos W1000, and Exynos Modem 5123, contact your device manufacturer (OEM) for availability of firmware updates that incorporate Samsung's fix.
Workarounds
- Avoid connecting to untrusted or unknown cellular networks
- Enable airplane mode when operating in potentially hostile RF environments
- Use Wi-Fi connectivity as an alternative where cellular exposure is a concern
- For enterprise deployments, consider mobile device management (MDM) policies that restrict cellular connectivity in high-risk scenarios
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
