CVE-2021-33107: Intel AMT SDK Information Disclosure Flaw

CVE-2021-33107 Overview

CVE-2021-33107 is an insufficiently protected credentials vulnerability affecting the USB provisioning mechanism in Intel Active Management Technology (AMT) SDK, Intel Setup and Configuration Software (SCS), and Intel Management Engine BIOS Extension (MEBx). This security flaw allows an unauthenticated attacker with physical access to a vulnerable system to potentially extract sensitive credential information through the USB provisioning interface.

Intel AMT is an enterprise-grade remote management technology built into Intel vPro platforms, enabling IT administrators to remotely manage, repair, and protect networked computing assets. The USB provisioning feature allows administrators to configure AMT settings via USB storage devices, which is particularly useful for initial system setup or in scenarios where network-based provisioning is unavailable.

Critical Impact

Physical access exploitation could lead to disclosure of AMT provisioning credentials, potentially compromising enterprise remote management infrastructure and enabling unauthorized system control.

Affected Products

• Intel Active Management Technology Software Development Kit before version 16.0.3
• Intel Setup and Configuration Software before version 12.2
• Intel Management Engine BIOS Extension before versions 11.0.0.0012, 12.0.0.0011, 14.0.0.0004, and 15.0.0.0004
• Multiple Intel Core i3, i5, i7, and i9 processors (7th through 10th generation)
• Intel Xeon processors with vPro support
• Various Intel chipsets including B560, H570, Q570, W580, Z590, and others

Discovery Timeline

• February 9, 2022 - CVE-2021-33107 published to NVD
• May 5, 2025 - Last updated in NVD database

Technical Details for CVE-2021-33107

Vulnerability Analysis

This vulnerability stems from inadequate protection of credential data during the USB provisioning process for Intel AMT. When administrators use USB-based provisioning to configure AMT on supported systems, the credentials and configuration data stored on or transmitted via the USB interface are not sufficiently protected against physical access attacks.

The vulnerability specifically affects the credential handling mechanisms within the provisioning workflow, where sensitive authentication materials may be exposed to an attacker who has physical access to the target system during or after the provisioning process. This represents a weakness in the design of the credential storage and transmission mechanisms rather than a traditional memory corruption or injection flaw.

Root Cause

The root cause of CVE-2021-33107 is classified under CWE-522 (Insufficiently Protected Credentials). The vulnerable components fail to implement adequate cryptographic protection or access controls for credentials used during USB-based AMT provisioning. This deficiency allows credential data to be accessible or recoverable by attackers with physical access to the system, USB storage device, or the provisioning communication channel.

The inadequate protection may manifest as:

• Credentials stored in cleartext or weakly encrypted format on USB provisioning media
• Insufficient authentication before credential disclosure during the provisioning handshake
• Lack of secure memory handling for credential data during the provisioning process

Attack Vector

Exploitation of CVE-2021-33107 requires physical access to a vulnerable system. An attacker would need to be physically present and able to interact with the target machine's USB interface or access USB provisioning media used for AMT configuration.

The attack scenario involves an unauthenticated attacker leveraging physical access to extract credential information from the USB provisioning process. This could be accomplished through direct physical access to a machine during provisioning, recovery of discarded or stolen USB provisioning media, or interception of the provisioning data flow when physical access to the system is available.

Given the physical access requirement, this vulnerability is most relevant in scenarios where attackers have insider access, physical penetration of facilities, or access to decommissioned or stolen equipment that retains provisioning data.

Detection Methods for CVE-2021-33107

Indicators of Compromise

• Unauthorized USB device connections on systems with Intel AMT enabled, particularly during non-standard hours
• Unexpected access to Intel MEBx configuration interfaces
• Evidence of AMT configuration changes not authorized by IT administrators
• USB provisioning media found in unexpected locations or accessed by unauthorized personnel

Detection Strategies

• Monitor physical access logs for server rooms and areas containing Intel vPro-enabled systems
• Implement USB device whitelisting and logging on enterprise endpoints
• Deploy endpoint detection solutions that alert on unexpected Intel AMT configuration changes
• Conduct periodic audits of AMT configuration states across managed systems

Monitoring Recommendations

• Enable detailed logging for Intel AMT provisioning events where available
• Configure SIEM solutions to correlate physical access events with system configuration changes
• Establish baseline AMT configurations and monitor for deviations
• Implement physical security controls around systems during provisioning operations

How to Mitigate CVE-2021-33107

Immediate Actions Required

• Update Intel AMT SDK to version 16.0.3 or later
• Update Intel Setup and Configuration Software to version 12.2 or later
• Update Intel MEBx firmware to patched versions (11.0.0.0012, 12.0.0.0011, 14.0.0.0004, or 15.0.0.0004 depending on platform)
• Review and audit any USB provisioning media currently in use for potential credential exposure
• Restrict physical access to systems during and after AMT provisioning operations

Patch Information

Intel has released security updates addressing this vulnerability as documented in Intel Security Advisory SA-00575 and Intel Security Advisory SA-00601. Organizations should apply the appropriate firmware and software updates for their specific Intel platforms through their standard update mechanisms or by obtaining updates directly from Intel or their system manufacturers.

Workarounds

• Disable USB provisioning for Intel AMT if not required and use network-based provisioning methods instead
• Implement strict physical security controls around systems during AMT provisioning
• Securely destroy USB provisioning media after use rather than reusing or storing it
• Consider host-based USB device control policies to prevent unauthorized USB provisioning attempts

# Example: Disable USB storage on Linux systems as an additional control
# Add to /etc/modprobe.d/disable-usb-storage.conf
echo "install usb-storage /bin/true" | sudo tee /etc/modprobe.d/disable-usb-storage.conf
echo "blacklist usb-storage" | sudo tee -a /etc/modprobe.d/disable-usb-storage.conf

# Verify Intel ME firmware version on Linux (requires intel-me-tools)
# sudo mei-amt-status

# Check AMT provisioning state via Windows PowerShell
# Get-CimInstance -Namespace root\Intel_ME -ClassName ME_System | Select-Object AMTMode, AMTState