CVE-2025-58343: Samsung Exynos 980 Firmware DoS Vulnerability

CVE-2025-58343 Overview

A memory exhaustion vulnerability has been discovered in the Wi-Fi driver for Samsung Mobile Processor and Wearable Processor Exynos chipsets. The vulnerability exists in the /proc/driver/unifi0/create_tspec write operation interface, which fails to properly validate the size of user-supplied buffer data before allocating kernel memory. This allows a local attacker to trigger unbounded memory allocation, leading to kernel memory exhaustion and denial of service conditions.

Critical Impact

Local attackers can cause complete system denial of service by exhausting kernel memory through the vulnerable Wi-Fi driver interface, potentially rendering affected Samsung mobile devices and wearables unresponsive.

Affected Products

• Samsung Exynos 980 (Mobile Processor) and Firmware
• Samsung Exynos 850 (Mobile Processor) and Firmware
• Samsung Exynos 1080, 1280, 1330, 1380, 1480, 1580 (Mobile Processors) and Firmware
• Samsung Exynos W920, W930, W1000 (Wearable Processors) and Firmware

Discovery Timeline

• February 3, 2026 - CVE-2025-58343 published to NVD
• February 5, 2026 - Last updated in NVD database

Technical Details for CVE-2025-58343

Vulnerability Analysis

This vulnerability is classified under CWE-770 (Allocation of Resources Without Limits or Throttling). The Wi-Fi driver's TSPEC (Traffic Specification) creation interface does not implement proper bounds checking on incoming write operations. When a user writes to the /proc/driver/unifi0/create_tspec file, the driver allocates kernel memory based on the size of the buffer provided without validating whether the requested allocation is within reasonable limits.

The attack requires local access to the device, meaning an attacker would need to have already gained some level of access to the Android system. However, no special privileges are required to exploit this vulnerability, and no user interaction is needed. The impact is limited to availability—there is no confidentiality or integrity impact, but successful exploitation results in complete denial of service as the kernel runs out of memory.

Root Cause

The root cause is improper resource allocation in the Samsung UniFi Wi-Fi driver's proc filesystem interface. The create_tspec write handler accepts user-controlled buffer sizes and passes them directly to kernel memory allocation functions without implementing maximum size restrictions or resource throttling. This allows attackers to request arbitrarily large memory allocations that quickly exhaust available kernel memory.

Attack Vector

The attack vector is local, requiring the attacker to execute code on the affected device. An attacker with local access can write specially crafted data with a large buffer size specification to the /proc/driver/unifi0/create_tspec file. By repeatedly triggering large memory allocations or by specifying an extremely large buffer in a single operation, the attacker can exhaust kernel memory resources.

The vulnerability resides in the proc filesystem interface of the UniFi Wi-Fi driver. When processing write operations to the create_tspec entry, the driver fails to validate the size parameter before performing memory allocation. This allows an attacker to specify arbitrarily large values, triggering kernel memory exhaustion. For technical details, refer to the Samsung Security Advisory for CVE-2025-58343.

Detection Methods for CVE-2025-58343

Indicators of Compromise

• Unusual write activity to /proc/driver/unifi0/create_tspec from non-system processes
• Kernel memory allocation failures or out-of-memory (OOM) killer activations
• System instability or unresponsiveness following Wi-Fi driver operations
• Abnormal memory consumption patterns in kernel space

Detection Strategies

• Monitor proc filesystem access patterns for suspicious write operations to Wi-Fi driver interfaces
• Implement kernel-level auditing for memory allocation requests exceeding normal thresholds
• Track OOM killer events and correlate with Wi-Fi driver activity
• Deploy mobile device management (MDM) solutions to detect anomalous application behavior

Monitoring Recommendations

• Enable kernel memory allocation auditing on devices with affected Exynos processors
• Configure alerts for repeated access attempts to /proc/driver/unifi0/ directory entries
• Monitor system logs for memory exhaustion warnings or OOM events
• Track application behavior patterns that involve direct proc filesystem manipulation

How to Mitigate CVE-2025-58343

Immediate Actions Required

• Apply the latest firmware updates from Samsung for affected Exynos processors
• Restrict access to developer modes and debugging features on production devices
• Review and limit application permissions, particularly those requesting low-level system access
• Monitor devices for signs of unusual memory consumption or system instability

Patch Information

Samsung has acknowledged this vulnerability and provided security updates. Device manufacturers using affected Exynos processors should obtain the patched firmware from Samsung and distribute updates to end users. Consult the Samsung Product Security Updates page for the latest patch availability and the CVE-2025-58343 specific advisory for detailed remediation guidance.

Workarounds

• Limit physical access to devices and disable USB debugging when not required
• Use mobile device management (MDM) policies to restrict installation of untrusted applications
• Consider disabling Wi-Fi functionality temporarily on high-security devices until patches are applied
• Implement application whitelisting to prevent unauthorized code execution

As this is a kernel-level driver vulnerability, configuration-based workarounds are limited. The primary mitigation is applying the vendor-provided firmware update. Organizations managing fleets of Samsung devices should prioritize firmware updates through their MDM infrastructure.