CVE-2025-58342: Samsung Exynos Firmware DoS Vulnerability

CVE-2025-58342 Overview

A resource exhaustion vulnerability has been discovered in the Wi-Fi driver used by multiple Samsung Exynos mobile and wearable processors. The vulnerability exists in the handling of write operations to /proc/driver/unifi0/uapsd, where unbounded memory allocation occurs when processing a large buffer. This flaw allows a local attacker to exhaust kernel memory, resulting in a denial of service condition on affected devices.

Critical Impact

Local attackers can trigger kernel memory exhaustion on Samsung mobile devices and wearables powered by vulnerable Exynos processors, causing system instability or crashes.

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

• 2026-02-03 - CVE-2025-58342 published to NVD
• 2026-02-05 - Last updated in NVD database

Technical Details for CVE-2025-58342

Vulnerability Analysis

This vulnerability is classified as CWE-770 (Allocation of Resources Without Limits or Throttling). The Wi-Fi driver in Samsung Exynos processors fails to properly validate or limit the size of buffers during write operations to the /proc/driver/unifi0/uapsd interface. When a malicious actor supplies an excessively large buffer, the driver attempts to allocate memory without bounds checking, leading to kernel memory exhaustion.

The attack requires local access to the device, meaning an attacker would need to execute malicious code on the target system. However, this could be achieved through a malicious application or by chaining with another vulnerability that provides initial code execution. The impact is limited to availability—the vulnerability does not allow for data theft or code execution, but can render the device unusable until rebooted.

Root Cause

The root cause lies in improper input validation within the Wi-Fi driver's proc filesystem handler. When processing write operations to the UAPSD (Unscheduled Automatic Power Save Delivery) configuration interface at /proc/driver/unifi0/uapsd, the driver accepts user-supplied buffer sizes without implementing appropriate bounds checking or memory allocation limits. This allows arbitrarily large memory allocations in kernel space, which depletes available system memory.

Attack Vector

An attacker with local access to an affected device can exploit this vulnerability by writing a specially crafted large buffer to the /proc/driver/unifi0/uapsd file. The attack does not require user interaction and can be performed without elevated privileges if the proc file is accessible. The exploitation causes the kernel to continuously allocate memory until the system becomes unresponsive.

The attack flow involves:

1. Gaining local access to the device (through a malicious app or other means)
2. Opening the vulnerable proc file for writing
3. Submitting an excessively large buffer to trigger unbounded memory allocation
4. Repeating as necessary to exhaust kernel memory resources

Detection Methods for CVE-2025-58342

Indicators of Compromise

• Unusual memory consumption spikes in kernel space
• System slowdown or unresponsiveness on Samsung devices with Exynos processors
• Repeated access attempts to /proc/driver/unifi0/uapsd
• Kernel out-of-memory (OOM) killer events or kernel panics

Detection Strategies

• Monitor for abnormal write operations to /proc/driver/unifi0/uapsd with large buffer sizes
• Implement kernel memory usage monitoring with alerts for rapid depletion
• Track process behavior for applications attempting to access Wi-Fi driver proc interfaces
• Use endpoint detection tools to identify resource exhaustion attack patterns

Monitoring Recommendations

• Enable kernel memory auditing on managed Samsung mobile devices
• Configure alerts for OOM killer invocations on affected Exynos-based devices
• Deploy mobile threat defense solutions capable of detecting denial of service attacks
• Monitor for applications with suspicious proc filesystem access patterns

How to Mitigate CVE-2025-58342

Immediate Actions Required

• Apply Samsung firmware updates as soon as they become available
• Restrict installation of applications from untrusted sources on affected devices
• Review and remove any suspicious applications that may have local access
• Consider device enrollment in mobile device management (MDM) solutions for policy enforcement

Patch Information

Samsung has published security advisories for this vulnerability. Organizations should review the Samsung Product Security Updates page and the specific Samsung CVE-2025-58342 Advisory for detailed patching instructions and firmware update availability for affected Exynos processors.

Device manufacturers using Samsung Exynos chipsets should contact Samsung for updated driver packages and integrate fixes into their firmware update cycles.

Workarounds

• Limit application installation to trusted sources (e.g., official app stores) to reduce local exploit risk
• Implement application whitelisting policies through MDM solutions on enterprise devices
• Monitor device behavior for signs of resource exhaustion attacks
• Restrict physical access to devices where sensitive operations are performed

# Example: Monitoring proc file access on rooted/development Android devices
# Note: Requires appropriate permissions and is for detection purposes only
adb shell "cat /proc/kmsg | grep -i unifi0"