CVE-2020-8752: Intel AMT Privilege Escalation Flaw

CVE-2020-8752 Overview

CVE-2020-8752 is a critical out-of-bounds write vulnerability affecting the IPv6 subsystem in Intel Active Management Technology (AMT) and Intel Standard Manageability (ISM) firmware. This vulnerability allows an unauthenticated attacker to potentially achieve escalation of privileges through network access, making it a significant threat to enterprise environments where Intel AMT is deployed for remote management capabilities.

Intel AMT is a hardware-based technology that provides remote out-of-band management of enterprise systems, operating independently of the host operating system. The IPv6 subsystem vulnerability allows malicious network packets to trigger memory corruption, potentially enabling complete system compromise without requiring any user interaction or prior authentication.

Critical Impact

Unauthenticated remote attackers can exploit this vulnerability over the network to gain elevated privileges on affected Intel AMT and ISM systems, potentially leading to complete system compromise.

Affected Products

• Intel Active Management Technology Firmware versions before 11.8.80, 11.12.80, 11.22.80, 12.0.70, 14.0.45
• Intel Standard Manageability versions before 11.8.80, 11.12.80, 11.22.80, 12.0.70, 14.0.45
• NetApp Cloud Backup (utilizing affected Intel components)

Discovery Timeline

• November 12, 2020 - CVE-2020-8752 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2020-8752

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), occurring within the IPv6 network stack implementation of Intel AMT and ISM firmware. The out-of-bounds write condition allows data to be written beyond the boundaries of allocated memory buffers when processing specially crafted IPv6 packets.

The vulnerability is particularly severe because Intel AMT operates at the firmware level, below the operating system. This means traditional endpoint security solutions running at the OS level cannot detect or prevent exploitation. The remote, unauthenticated nature of the attack vector, combined with the potential for privilege escalation, creates a critical risk for enterprise environments.

Successful exploitation could allow an attacker to execute arbitrary code within the AMT firmware context, potentially enabling persistent access that survives operating system reinstallation, modification of system firmware, and lateral movement within the network to other AMT-enabled systems.

Root Cause

The root cause of CVE-2020-8752 is insufficient bounds checking in the IPv6 packet processing routines within the Intel AMT and ISM firmware. When the IPv6 subsystem receives network packets, it fails to properly validate the length or structure of certain packet fields before writing data to internal memory buffers. This missing validation allows an attacker to supply malformed IPv6 packets that cause writes beyond the intended buffer boundaries, corrupting adjacent memory regions.

Attack Vector

The attack vector for CVE-2020-8752 is network-based and requires no authentication or user interaction. An attacker with network access to the AMT/ISM service can send specially crafted IPv6 packets to trigger the out-of-bounds write condition.

The exploitation scenario typically involves:

1. Network reconnaissance to identify systems with Intel AMT enabled and accessible
2. Crafting malicious IPv6 packets designed to trigger the out-of-bounds write
3. Sending the malicious packets to the target system's AMT network interface
4. Leveraging the memory corruption to achieve code execution within the AMT firmware context
5. Escalating privileges to gain full control over the target system

The vulnerability is exploitable from the network without requiring local access, making it particularly dangerous for systems with AMT interfaces exposed to untrusted networks.

Detection Methods for CVE-2020-8752

Indicators of Compromise

• Unexpected or anomalous IPv6 traffic targeting Intel AMT ports (typically TCP port 16992 for HTTP or 16993 for HTTPS)
• Unusual network connections originating from the AMT network interface
• Firmware modifications or unexpected AMT configuration changes
• System instability or crashes related to AMT functionality

Detection Strategies

• Deploy network intrusion detection systems (IDS) with signatures for anomalous IPv6 traffic patterns targeting AMT services
• Monitor network traffic for connections to Intel AMT management ports from unauthorized sources
• Implement asset inventory processes to identify all systems with Intel AMT enabled
• Use firmware integrity monitoring solutions to detect unauthorized modifications to AMT firmware

Monitoring Recommendations

• Enable logging for all AMT network interface activity and forward logs to a centralized SIEM
• Monitor for CVE-2020-8752 exploitation attempts using threat intelligence feeds
• Configure alerts for any IPv6 traffic anomalies on AMT-enabled systems
• Regularly audit AMT firmware versions across the enterprise to ensure patching compliance

How to Mitigate CVE-2020-8752

Immediate Actions Required

• Identify all systems running vulnerable Intel AMT or ISM firmware versions
• Apply the latest firmware updates from Intel as documented in Intel Security Advisory SA-00391
• If immediate patching is not possible, disable or restrict network access to AMT services
• Segment AMT management traffic to isolated networks inaccessible from untrusted sources

Patch Information

Intel has released firmware updates to address CVE-2020-8752. Organizations should update to the following minimum versions:

• Intel AMT/ISM version 11.8.80 or later for the 11.8.x branch
• Intel AMT/ISM version 11.12.80 or later for the 11.12.x branch
• Intel AMT/ISM version 11.22.80 or later for the 11.22.x branch
• Intel AMT/ISM version 12.0.70 or later for the 12.x branch
• Intel AMT/ISM version 14.0.45 or later for the 14.x branch

Detailed patch information is available from the Intel Security Advisory SA-00391. NetApp customers should also review the NetApp Security Advisory for affected Cloud Backup deployments.

Workarounds

• Disable Intel AMT if the functionality is not required for system management
• Restrict network access to AMT interfaces using firewall rules, allowing connections only from trusted management networks
• Disable IPv6 on the AMT interface if IPv6 management is not required
• Implement network segmentation to isolate AMT management traffic from general network traffic

# Example: Block external access to AMT ports using iptables
iptables -A INPUT -p tcp --dport 16992 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 16993 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 16992 -j DROP
iptables -A INPUT -p tcp --dport 16993 -j DROP