CVE-2025-43706: Samsung Exynos Processor DoS Vulnerability

CVE-2025-43706 Overview

A Denial of Service vulnerability has been discovered in the Layer 2 (L2) component of multiple Samsung Mobile Processors, Wearable Processors, and Modems. The vulnerability stems from incorrect handling of Radio Resource Control (RRC) packets, which can be exploited to cause service disruption on affected devices. This flaw affects a wide range of Samsung Exynos chipsets used in smartphones, wearables, and modem implementations.

Critical Impact

This network-exploitable vulnerability allows remote attackers to disrupt device availability without requiring authentication or user interaction. Devices utilizing affected Samsung Exynos processors may become unresponsive when targeted with maliciously crafted RRC packets.

Affected Products

• Samsung Exynos 980, 990, 850, 1080, 2400, 1580 Mobile Processors
• Samsung Exynos 9110, W920, W930 Wearable Processors
• Samsung Exynos Modem 5123 and Modem 5400

Discovery Timeline

• 2026-01-05 - CVE-2025-43706 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-43706

Vulnerability Analysis

This vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the affected L2 layer implementation fails to properly constrain resource allocation when processing RRC packets. The Radio Resource Control protocol is a critical component of cellular communication that manages signaling between mobile devices and the network. When malformed or specially crafted RRC packets are processed, the firmware fails to handle them correctly, leading to resource exhaustion and subsequent denial of service.

The attack can be executed remotely over the network without any privileges or user interaction, making it particularly concerning for mobile and wearable devices that are constantly connected to cellular networks. The impact is limited to availability—there is no evidence that confidentiality or integrity can be compromised through this vulnerability.

Root Cause

The root cause lies in improper input validation within the L2 (Layer 2) packet processing logic of Samsung Exynos baseband firmware. When RRC packets with unexpected or malformed content are received, the processor fails to implement appropriate bounds checking or error handling. This results in uncontrolled resource consumption that can exhaust system resources, causing the baseband processor to become unresponsive.

Attack Vector

The attack vector is network-based, leveraging the cellular communication infrastructure. An attacker with the ability to send RRC packets to a target device—either through a rogue base station, compromised network equipment, or by exploiting carrier network access—can trigger the denial of service condition. The vulnerability does not require authentication, and the attack can be executed without any interaction from the device user.

The attack exploits the baseband processor's handling of RRC signaling messages. Since RRC operates at Layer 3 of the radio protocol stack but relies on Layer 2 for transport, malformed packets processed at L2 can trigger the vulnerability before upper-layer validation occurs. Technical details regarding the specific malformed packet structure are available through the Samsung Security Advisory.

Detection Methods for CVE-2025-43706

Indicators of Compromise

• Unexpected device reboots or baseband crashes without apparent cause
• Loss of cellular connectivity following reception of suspicious network traffic
• Repeated modem subsystem failures in device logs
• Unusual RRC protocol errors logged by the baseband processor

Detection Strategies

• Monitor baseband firmware crash reports and modem subsystem restarts
• Implement network-level monitoring for anomalous RRC packet patterns at carrier infrastructure
• Deploy SentinelOne Singularity Mobile to detect and alert on device instability patterns
• Review device telemetry for repeated connectivity drops that may indicate exploitation attempts

Monitoring Recommendations

• Enable enhanced logging on mobile device management (MDM) platforms to capture baseband-related events
• Implement centralized crash reporting to identify patterns across device fleets
• Work with carrier partners to monitor for rogue base station activity
• Utilize SentinelOne's threat intelligence feeds to stay updated on active exploitation attempts

How to Mitigate CVE-2025-43706

Immediate Actions Required

• Apply the latest firmware updates from Samsung for affected Exynos processors
• Monitor Samsung's security bulletins for patch availability specific to your device models
• For enterprise environments, prioritize firmware updates for devices using affected chipsets
• Consider network-level protections where feasible to filter malicious RRC traffic

Patch Information

Samsung has acknowledged this vulnerability and published security guidance. Organizations and individuals using affected Samsung Exynos processors should consult the Samsung Product Security Updates page for the latest firmware patches. Device manufacturers that integrate these processors should coordinate with Samsung for updated baseband firmware and distribute updates to end users through their normal update channels.

Workarounds

• No complete workarounds exist since the vulnerability resides in baseband firmware
• Minimize exposure by keeping devices updated with the latest available firmware
• Enterprise users should implement mobile threat defense solutions like SentinelOne Singularity Mobile to detect anomalous device behavior
• Consider network segmentation and monitoring at carrier level where possible
• Temporarily disable cellular connectivity and use Wi-Fi calling if immediate patching is not possible and risk is deemed critical

Firmware updates should be applied as the primary mitigation. For environments where immediate patching is not feasible, enhanced monitoring through SentinelOne's mobile security platform can provide visibility into potential exploitation attempts and device health anomalies.