On November 28, 2017 a software developer (Lemi Orhan Ergin) reported a critical flaw in macOS High Sierra which allows any local user to log in as root without a password after multiple attempts.

Detecting macOS High Sierra root account vulnerability (CVE-2017-13872)

An issue was discovered in certain Apple products. macOS High Sierra before Security Update 2017-001 is affected. The issue involves the "Directory Utility" component. It allows attackers to obtain administrator access without a password via certain interactions involving entry of the root user name.

The remote host is running a version of macOS that is 10.13.x prior to 10.13.2. It is, therefore, affected by multiple vulnerabilities in the following components :

 - Apache
 - curl
 - Directory Utility
 - IOAcceleratorFamily
 - IOKit
 - Intel Graphics Driver
 - Kernel
 - Mail
 - Mail Drafts
 - OpenSSL
 - Screen Sharing Server

Note that successful exploitation of the most serious issues can result in arbitrary code execution.

The remote host is running Mac OS X 10.11.6 or Mac OS X 10.12.6 and is missing a security update. It is therefore, affected by multiple vulnerabilities affecting the following components :

  - apache
  - curl
  - IOAcceleratorFamily
  - IOKit
  - Kernel
  - OpenSSL
  - Screen Sharing Server

The remote host is running a version of Mac OS X that is 10.13.x prior to 10.13.2. It is, therefore, affected by multiple vulnerabilities in the following components :

  - apache
  - curl
  - Directory Utility
  - IOAcceleratorFamily
  - IOKit
  - Intel Graphics Driver
  - Kernel
  - Mail
  - Mail Drafts
  - OpenSSL
  - Screen Sharing Server

Note that successful exploitation of the most serious issues can result in arbitrary code execution.

The remote host is affected by an authentication bypass vulnerability.
A local attacker or a remote attacker with credentials for a standard user account has the ability to blank out the root account password.
This can allow an authenticated attacker to escalate privileges to root and execute commands and read files as a system administrator.
A remote attacker without credentials can set passwords on certain disabled accounts.

Note that if this plugin is successful, Nessus has set the password on the 'nobody' account to 'nessus', and you will need to reset this password/re-disable this account to clean up.

The remote host is running a version of macOS that has a root authentication bypass vulnerability. A local attacker or a remote attacker with credentials for a standard user account has the ability to blank out the root account password. This can allow an attacker to escalate privileges to root and execute commands and read files as a system administrator.

The remote host is running a version of MacOS 10.13 or 10.13.1 that is missing a security update. It is, therefore, affected by a root authentication bypass vulnerability. A local attacker or a remote attacker with credentials for a standard user account has the ability to blank out the root account password. This can allow an attacker to escalate privileges to root and execute commands and read files as a system administrator.

ID	Name	Product	Family	Severity
700513	macOS 10.13.x < 10.13.2 Multiple Vulnerabilities (Meltdown)	Nessus Network Monitor	Operating System Detection	critical
105081	macOS and Mac OS X Multiple Vulnerabilities (Security Update 2017-002 and 2017-005)	Nessus	MacOS X Local Security Checks	high
105080	macOS 10.13.x < 10.13.2 Multiple Vulnerabilities (Meltdown)	Nessus	MacOS X Local Security Checks	high
105003	macOS 10.13 Authentication Bypass Remote Check (CVE-2017-13872)	Nessus	Misc.	high
104848	macOS 10.13 root Authentication Bypass Direct Check	Nessus	MacOS X Local Security Checks	high
104814	MacOS 10.13 root Authentication Bypass (Security Update 2017-001)	Nessus	MacOS X Local Security Checks	high

Detections

Analytics

CVE-2017-13872

high

Tenable Plugins

critical

high

high

high

high

high