CVE-2025-58340: Samsung Exynos 980 Firmware DOS Vulnerability

CVE-2025-58340 Overview

A memory exhaustion vulnerability has been discovered in the Wi-Fi driver used by Samsung Mobile and Wearable Processor Exynos chipsets. The flaw exists in the /proc/driver/unifi0/send_delts write operation, where unbounded memory allocation occurs when processing large buffers, potentially leading to kernel memory exhaustion and denial of service conditions.

Critical Impact

Local attackers can trigger kernel memory exhaustion through unbounded memory allocation in the Wi-Fi driver, causing system instability or denial of service on affected Samsung devices.

Affected Products

• Samsung Exynos 980, 850, 1080, 1280, 1330, 1380, 1480, 1580 Mobile Processors
• Samsung Exynos W920, W930, W1000 Wearable Processors
• Associated firmware for all affected Exynos chipsets

Discovery Timeline

• February 3, 2026 - CVE-2025-58340 published to NVD
• February 5, 2026 - Last updated in NVD database

Technical Details for CVE-2025-58340

Vulnerability Analysis

This vulnerability is classified as CWE-770 (Allocation of Resources Without Limits or Throttling). The Wi-Fi driver in affected Samsung Exynos processors fails to properly validate or limit the size of memory allocations when processing write operations to the /proc/driver/unifi0/send_delts interface.

The vulnerability requires local access to exploit, meaning an attacker must have already gained some level of access to the target device. However, no user interaction is required, and the attack can be performed without any special privileges. The primary impact is on system availability, as successful exploitation leads to kernel memory exhaustion.

Root Cause

The root cause of this vulnerability lies in insufficient input validation within the Wi-Fi driver's proc filesystem handler. When a write operation is performed to /proc/driver/unifi0/send_delts, the driver allocates memory based on the buffer size specified by the user without implementing proper bounds checking or memory allocation limits. This allows an attacker to request arbitrarily large memory allocations, eventually exhausting available kernel memory resources.

Attack Vector

The attack requires local access to the device and the ability to write to the /proc/driver/unifi0/send_delts interface. An attacker with local access can craft write operations with excessively large buffer sizes, triggering unbounded memory allocations in kernel space.

The exploitation mechanism involves repeatedly writing large buffers to the vulnerable proc interface, causing the kernel to allocate memory without proper limits. As memory is consumed without release, the system eventually becomes unstable or unresponsive as kernel memory resources are depleted.

This type of resource exhaustion attack can be particularly impactful on mobile and wearable devices where memory resources are more constrained compared to traditional computing platforms.

Detection Methods for CVE-2025-58340

Indicators of Compromise

• Unusual memory consumption patterns in kernel space on affected Samsung Exynos devices
• Repeated access attempts or write operations to /proc/driver/unifi0/send_delts
• System instability or unresponsiveness related to Wi-Fi driver operations
• Kernel out-of-memory (OOM) events occurring without legitimate high-memory workloads

Detection Strategies

• Monitor proc filesystem access patterns, specifically targeting /proc/driver/unifi0/send_delts
• Implement kernel memory monitoring to detect abnormal allocation patterns
• Deploy endpoint detection solutions capable of monitoring low-level system calls and driver interactions
• Review system logs for OOM killer activity or Wi-Fi driver-related errors

Monitoring Recommendations

• Enable kernel memory allocation auditing where supported
• Implement alerting for unusual proc filesystem write operations targeting driver interfaces
• Monitor device stability metrics and correlate with Wi-Fi driver activity
• Consider deploying mobile device management (MDM) solutions with security monitoring capabilities

How to Mitigate CVE-2025-58340

Immediate Actions Required

• Review and apply the latest firmware updates from Samsung for affected Exynos processors
• Restrict local access to affected devices to trusted users only
• Monitor devices for signs of exploitation or unusual system behavior
• Consider temporarily disabling Wi-Fi functionality on critical devices until patches are applied

Patch Information

Samsung has released security updates to address this vulnerability. Organizations and users should apply the latest firmware updates for affected Exynos processors. Detailed patch information and firmware downloads are available through the Samsung Product Security Updates portal and the Samsung CVE-2025-58340 Advisory.

Workarounds

• Limit local access to affected devices through access control policies
• Implement application sandboxing to restrict access to sensitive proc interfaces
• Monitor and audit file system operations on sensitive kernel interfaces
• Deploy endpoint protection solutions that can detect and block resource exhaustion attacks

# Example: Monitor access to the vulnerable proc interface
# Note: Implementation varies by Android security framework
auditctl -w /proc/driver/unifi0/send_delts -p w -k wifi_driver_delts