CVE-2025-47904: Microchip Time Provider 4100 RCE Flaw

CVE-2025-47904 Overview

CVE-2025-47904 is a Download of Code Without Integrity Check vulnerability (CWE-494) affecting the Microchip Time Provider 4100 timing device. This firmware vulnerability enables attackers to perform malicious manual software updates due to the absence of proper integrity verification during the upgrade process. The Time Provider 4100 is a precision timing device commonly deployed in critical infrastructure environments including telecommunications, financial services, and power grid synchronization systems.

Critical Impact

Attackers with local access and high privileges can inject malicious firmware into the Time Provider 4100 device, potentially compromising time synchronization integrity across dependent critical infrastructure systems.

Affected Products

• Microchip Time Provider 4100 versions prior to 2.5

Discovery Timeline

• 2026-02-24 - CVE CVE-2025-47904 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2025-47904

Vulnerability Analysis

This vulnerability stems from a fundamental design flaw in the firmware update mechanism of the Microchip Time Provider 4100. The device fails to implement cryptographic integrity verification when processing software updates, allowing unsigned or improperly signed firmware packages to be installed. This represents a classic case of CWE-494 (Download of Code Without Integrity Check), where the system accepts code from external sources without validating its authenticity or integrity.

The attack requires local access to the device and high privileges, with additional conditions that must be met for successful exploitation. If successfully exploited, an attacker can achieve high impact to system integrity while causing limited confidentiality and availability impacts to both the vulnerable system and connected systems that rely on its timing synchronization.

Root Cause

The root cause of this vulnerability is the absence of cryptographic signature verification in the Time Provider 4100's firmware upgrade process. Modern embedded systems should implement secure boot chains and code signing to ensure that only authorized firmware from the vendor can be installed. The Time Provider 4100 versions before 2.5 lack this critical security control, allowing arbitrary firmware images to be loaded onto the device without validation.

Attack Vector

The attack vector is local, requiring an attacker to have direct access to the Time Provider 4100 device with high-level privileges. The exploitation is not trivial—it requires specific preconditions to be present (high attack complexity with additional prerequisites). An attacker would need to:

1. Obtain local administrative access to the Time Provider 4100 device
2. Craft or obtain a malicious firmware image
3. Initiate the manual software update process with the unauthorized firmware
4. The device accepts and installs the firmware without verifying its authenticity

Once malicious firmware is installed, the attacker gains persistent control over the timing device, potentially manipulating time synchronization across all dependent systems.

Detection Methods for CVE-2025-47904

Indicators of Compromise

• Unexpected firmware version changes on Time Provider 4100 devices
• Audit log entries showing manual firmware updates by unauthorized personnel
• Timing anomalies or drift detected in systems synchronized with the affected device
• Unauthorized administrative access attempts to the device management interface

Detection Strategies

• Monitor firmware integrity through regular hash comparisons against known-good baseline images
• Implement network monitoring to detect unauthorized access to Time Provider 4100 management interfaces
• Enable and review device audit logs for unexpected firmware update activities
• Deploy endpoint detection solutions on systems that manage timing infrastructure

Monitoring Recommendations

• Establish firmware version baselines and alert on any deviations from approved versions
• Configure SIEM rules to correlate administrative access to timing devices with firmware change events
• Implement physical security monitoring for areas housing critical timing infrastructure
• Monitor time synchronization accuracy across dependent systems for anomalies

How to Mitigate CVE-2025-47904

Immediate Actions Required

• Upgrade all Microchip Time Provider 4100 devices to version 2.5 or later
• Restrict local administrative access to Time Provider 4100 devices to authorized personnel only
• Implement physical access controls to prevent unauthorized access to timing infrastructure
• Audit all recent firmware updates to verify authenticity of installed firmware

Patch Information

Microchip has addressed this vulnerability in Time Provider 4100 version 2.5, which implements proper integrity verification for firmware updates. Organizations should obtain the updated firmware from official Microchip distribution channels and verify the integrity of the update package before installation. Detailed information is available in the Microchip Security Vulnerability Report.

Workarounds

• Implement strict network segmentation to isolate Time Provider 4100 devices from untrusted networks
• Enable multi-factor authentication for administrative access to timing devices where supported
• Establish a change management process requiring dual authorization for any firmware updates
• Consider deploying out-of-band monitoring to verify firmware integrity on a scheduled basis

# Example: Network segmentation rule to restrict management access
# Restrict management interface access to authorized management VLAN only
iptables -A INPUT -i eth0 -p tcp --dport 443 -s 10.10.100.0/24 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 443 -j DROP

# Verify current firmware version (device-specific command)
# Consult Microchip documentation for device-specific verification procedures