CVE-2025-58476: Samsung Android Information Disclosure Flaw

CVE-2025-58476 Overview

CVE-2025-58476 is an out-of-bounds read vulnerability affecting the bootloader component in Samsung Android devices prior to SMR Dec-2025 Release 1. This vulnerability allows physical attackers with direct access to affected devices to read out-of-bounds memory, potentially exposing sensitive information stored in adjacent memory regions.

The vulnerability has been assigned a CVSS v3.1 base score of 4.6 (MEDIUM) with the vector string CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. This indicates that while physical access is required, successful exploitation requires no privileges or user interaction and can result in high confidentiality impact.

Critical Impact

Physical attackers can exploit this bootloader vulnerability to access out-of-bounds memory regions, potentially exposing cryptographic keys, secure boot secrets, or other sensitive data stored in device memory.

Affected Products

• Samsung Android 13.0 (all SMR releases prior to Dec-2025 Release 1)
• Samsung Android 14.0 (all SMR releases prior to Dec-2025 Release 1)
• Samsung Android 15.0 (all SMR releases prior to Dec-2025 Release 1)
• Samsung Android 16.0 (all SMR releases prior to Dec-2025 Release 1)

Discovery Timeline

• December 2, 2025 - CVE-2025-58476 published to NVD
• December 5, 2025 - Last updated in NVD database

Technical Details for CVE-2025-58476

Vulnerability Analysis

This vulnerability (CWE-125: Out-of-bounds Read) exists in the Samsung Android bootloader, a critical component responsible for initializing hardware and loading the operating system. Bootloaders operate at the lowest software level with the highest privileges, making vulnerabilities in this component particularly sensitive.

Out-of-bounds read vulnerabilities occur when software reads data from a memory location that is outside the bounds of the intended buffer or array. In the context of a bootloader, this can be especially dangerous as bootloader memory may contain:

• Secure boot keys and certificates
• Device encryption keys
• Hardware security module (HSM) secrets
• Trusted Execution Environment (TEE) initialization data
• Device-specific cryptographic material

The CVSS vector indicates physical access is required (AV:P), low attack complexity (AC:L), no privileges needed (PR:N), and no user interaction required (UI:N). The impact is limited to confidentiality (C:H/I:N/A:N), meaning data can be read but not modified or used to cause denial of service.

Root Cause

The root cause of CVE-2025-58476 stems from improper bounds checking in the bootloader's memory read operations. When processing certain inputs or data structures during the boot sequence, the bootloader fails to properly validate that memory access operations remain within allocated buffer boundaries. This allows attackers with physical access to craft inputs that cause the bootloader to read beyond intended memory boundaries.

Bootloader vulnerabilities of this nature typically arise from:

• Missing or inadequate array bounds validation
• Incorrect calculation of buffer sizes
• Integer overflow leading to undersized allocations
• Improper handling of user-controlled length fields

Attack Vector

Exploitation of CVE-2025-58476 requires physical access to an affected Samsung Android device. An attacker with such access could potentially exploit this vulnerability through methods such as:

1. Boot Mode Manipulation: Entering specialized boot modes (download mode, recovery mode) that may expose bootloader interfaces
2. USB/UART Interfaces: Using hardware debugging interfaces to send crafted commands to the bootloader
3. Modified Boot Images: Loading crafted boot images that trigger the out-of-bounds read condition
4. Hardware Probing: Using hardware debugging tools to interact with bootloader memory during the boot process

The physical access requirement significantly limits the attack surface, as remote exploitation is not possible. However, this vulnerability could be of particular interest to:

• Forensic investigators attempting to extract device data
• Sophisticated threat actors with temporary physical access to target devices
• Researchers analyzing device security mechanisms

Detection Methods for CVE-2025-58476

Indicators of Compromise

• Device boots into unexpected states or modes without user initiation
• Evidence of physical tampering with device hardware interfaces
• Unexpected debug logging or UART activity during device boot
• Signs of hardware debugging equipment connections (scratches near debug ports, removed covers)
• Boot logs showing abnormal memory access patterns

Detection Strategies

Device Integrity Monitoring:
Samsung Knox and similar enterprise security solutions can detect signs of bootloader tampering or unexpected boot sequences. Organizations should ensure Knox attestation is enabled and actively monitored.

Physical Security Controls:
Since this vulnerability requires physical access, detection strategies should focus on:

• USB device connection logging on managed devices
• Physical access logging for secure areas where devices are stored
• Tamper-evident seals or enclosures for high-security devices

Boot Verification:
Monitor for devices that fail Verified Boot or show signs of bootloader modification. Samsung's secure boot chain should report integrity failures if bootloader code or configuration has been modified.

Monitoring Recommendations

Organizations managing fleets of Samsung Android devices should:

1. Enable Knox Attestation: Ensure Samsung Knox is configured to verify device integrity at each boot and report anomalies
2. Monitor MDM Alerts: Configure Mobile Device Management solutions to alert on boot integrity failures
3. Implement Physical Security: Restrict physical access to sensitive devices and maintain access logs
4. Review Device Logs: Periodically review device logs for signs of unusual boot sequences or hardware interface activity
5. Track Firmware Versions: Maintain inventory of device firmware versions to identify unpatched devices

How to Mitigate CVE-2025-58476

Immediate Actions Required

• Apply the Samsung SMR Dec-2025 Release 1 security update to all affected devices immediately
• Implement strict physical access controls for devices containing sensitive data
• Enable Samsung Knox or equivalent device integrity monitoring
• Review and restrict access to device download mode and other bootloader interfaces
• Consider remote wipe capabilities for devices that may be physically compromised

Patch Information

Samsung has addressed this vulnerability in the SMR Dec-2025 Release 1 security maintenance release. The patch is available for Samsung Android versions 13.0, 14.0, 15.0, and 16.0.

Vendor Advisory:Samsung Mobile Security Update - December 2025

Organizations should prioritize deployment of this security update through their Mobile Device Management (MDM) solutions. The update addresses the out-of-bounds read condition by implementing proper bounds checking in the affected bootloader code paths.

EPSS Score: 0.02% probability of exploitation (4.632 percentile as of December 16, 2025), indicating relatively low likelihood of active exploitation, consistent with the physical access requirement.

Workarounds

If immediate patching is not possible, organizations should implement the following compensating controls:

Physical Security Hardening:
Implement enhanced physical security measures for affected devices, including restricted access to areas where devices are stored or used, tamper-evident seals, and comprehensive access logging.

Disable Debug Interfaces:
Where possible through MDM or device policy, disable or restrict access to device debug interfaces and download mode. This can be configured through Samsung Knox:

# Knox MDM Policy Configuration
# Restrict download mode and debug access

# Via Knox Configure or EMM console:
# 1. Navigate to Device Restrictions
# 2. Disable "Allow OEM Unlock"
# 3. Disable "USB Debugging"
# 4. Enable "Block Download Mode" if available for your device model

# For enterprise deployments, consider Knox Vault for additional bootloader protection

Implement Device Attestation:
Enable continuous device attestation to detect any signs of bootloader compromise or boot integrity failures. Configure your MDM solution to quarantine devices that fail attestation checks until they can be physically inspected and remediated.