CVE-2025-64305 Overview
CVE-2025-64305 is a sensitive data exposure vulnerability affecting MicroServer devices. The vulnerability occurs when the system copies parts of the firmware containing user and vendor secrets to an unencrypted external SD card during the boot process. An attacker with adjacent network access or physical access to the SD card can extract these plaintext secrets to modify vendor firmware or gain unauthorized administrative access to the web portal.
Critical Impact
Exposure of plaintext user and vendor secrets enables firmware modification and unauthorized administrative access to the management interface.
Affected Products
- MicroServer (all versions with SD card boot functionality)
Discovery Timeline
- 2026-01-07 - CVE CVE-2025-64305 published to NVD
- 2026-01-08 - Last updated in NVD database
Technical Details for CVE-2025-64305
Vulnerability Analysis
This vulnerability is classified under CWE-313 (Cleartext Storage in a File or on Disk), representing a fundamental violation of secure storage principles for sensitive credentials. During the boot sequence, MicroServer devices copy portions of system firmware to an externally accessible SD card without applying any encryption or access controls to protect the sensitive data contained within.
The exposed secrets include both user credentials and vendor-specific secrets that are embedded within the firmware. This design flaw creates two primary attack scenarios: firmware tampering and administrative access compromise. An attacker who obtains the SD card contents can extract authentication credentials for the web management portal, gaining full administrative control over the device. Additionally, the vendor secrets can be leveraged to create modified firmware images that the device will accept as legitimate.
Root Cause
The root cause is the insecure design decision to store sensitive firmware components on removable media without encryption. The system fails to implement proper cryptographic protection for data at rest, leaving user credentials and vendor secrets in cleartext format on the SD card. This violates fundamental security principles requiring encryption of sensitive data, particularly when stored on removable or externally accessible media.
Attack Vector
The attack requires adjacent network access to the target device. An attacker can exploit this vulnerability by:
- Gaining physical access to the external SD card slot on the MicroServer device
- Removing or cloning the SD card during or after the boot process
- Extracting the unencrypted firmware data containing plaintext secrets
- Using extracted user credentials to access the administrative web portal
- Alternatively, using vendor secrets to craft and deploy malicious firmware modifications
The adjacent network attack vector indicates that the attacker must be on the same network segment or have physical proximity to the device. No authentication is required, and no user interaction is needed for successful exploitation.
Detection Methods for CVE-2025-64305
Indicators of Compromise
- Unauthorized access attempts to the MicroServer web portal from unknown IP addresses
- Evidence of SD card removal or tampering on affected devices
- Firmware integrity check failures or unexpected firmware modifications
- Unusual administrative session activity or credential changes
Detection Strategies
- Monitor physical access logs and tamper detection mechanisms on MicroServer devices
- Implement file integrity monitoring on SD card contents to detect unauthorized reads or modifications
- Review authentication logs for successful logins from unexpected sources
- Deploy network monitoring to detect anomalous traffic patterns to affected devices
Monitoring Recommendations
- Enable comprehensive logging of all administrative access attempts and session activity
- Implement alerts for firmware modification events or integrity verification failures
- Monitor for unusual data exfiltration patterns from devices on the network segment
- Establish baseline behavior profiles for MicroServer devices to identify anomalies
How to Mitigate CVE-2025-64305
Immediate Actions Required
- Restrict physical access to MicroServer devices and their SD card slots
- Implement network segmentation to limit adjacent network exposure
- Rotate all administrative credentials that may have been exposed
- Review and audit all recent administrative access to affected devices
Patch Information
Organizations should consult the CISA ICS Advisory #26-006-01 for vendor-specific patch information and remediation guidance. Additional technical details are available in the GitHub CSAF Resource.
Workarounds
- Physically secure or remove SD cards from devices when not required for operation
- Implement additional access controls and monitoring on network segments containing vulnerable devices
- Deploy compensating controls such as tamper-evident seals on device enclosures
- Consider disabling SD card boot functionality if supported by device configuration
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
