Intel AMT/ISM/SBT Privilege Escalation and Remote Code Execution Vulnerability (CVE-2017-5689) Security Advisory

1. Vulnerability Overview & Root Cause

This vulnerability (CVE-2017-5689) is a critical privilege escalation flaw in the web-based management interface of Intel's hardware-based out-of-band (OOB) management technologies: Active Management Technology (AMT), Standard Manageability (ISM), and Small Business Technology (SBT). The root cause lies in a logical flaw within the HTTP Digest Authentication handler (CWE-269). When an attacker sends an authentication request with a blank or manipulated response hash, the internal validation logic incorrectly treats it as a successful authentication, bypassing password verification entirely and granting full administrative access.

2. Exploitation Mechanics & Attack Scenario

An attacker scans the network for target systems exposing the AMT web management ports (default TCP 16992 for HTTP or 16993 for HTTPS). Once an active port is identified, the attacker transmits a crafted HTTP POST/GET request containing a Digest authentication header where the response field is set to an empty string (""). The vulnerable firmware accepts this empty response as valid, bypassing the password check. This grants the attacker full access to the web UI or redirection ports (TCP 16994/16995), enabling hardware-level remote control (KVM), power management, and virtual media redirection.

3. Infrastructure & Business Impact

Because this vulnerability operates within the Intel Management Engine at a hardware level below the operating system, it is completely invisible to OS-level security controls such as Antivirus or Endpoint Detection and Response (EDR) agents. An attacker exploiting this flaw can gain persistent, low-level control over the system, modify firmware, install persistent backdoors, or manipulate data, posing an extreme risk to the confidentiality, integrity, and availability of the entire enterprise infrastructure.