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Microsoft Windows Privilege Escalation Vulnerability

A vulnerability has been discovered in the Microsoft Windows task scheduler that allows an authenticated attacker to obtain escalated privileges.
Threat ID:
CC-2646
Category:
Exploit
Threat Severity:
Medium
Threat Vector:
Vulnerability
Published:
30 August 2018 12:00 AM
Report a cyber attack: call 0300 303 5222 or email [email protected]

This content has been archived

This article no longer conforms to NHS Digital's standards for cyber alerts, and may contain outdated or inaccurate information. Use of this information contained in this page is at your own risk

Summary

A vulnerability has been discovered in the Microsoft Windows task scheduler that allows an authenticated attacker to obtain escalated privileges.

Affected platforms

The following platforms are known to be affected:

Microsoft Windows

  • Microsoft Windows - All versions

Threat details

A function in the task scheduler's Advanced Local Procedure Call (ALPC) interface fails to check permissions, so system files can be hijacked by any authenticated user. To exploit this vulnerability an attacker would need to obtain account credentials and device access, or use social engineering techniques to persuade a user to run malware.

The researcher who discovered the vulnerability published a proof of concept exploit on social media without allowing Microsoft the opportunity to develop an update, which means that zero-day attacks are possible at the time of publication.

For further information:

Remediation steps

Type Step

At the time of publication there is no indication of when an update that addresses this vulnerability will be released, but this is most likely to be included in the September 2018 Patch Tuesday updates.

To prevent and detect an infection in the meantime, ensure that:

  • A robust program of education and awareness training is delivered to users to ensure they don’t open attachments or follow links within unsolicited emails.
  • All operating systems, anti-virus and other security products are kept up-to-date.
  • All day-to-day computer activities such as email and internet are performed using non-administrative accounts.
  • Strong password policies are in place.
  • Network, proxy and firewall logs should be monitored for suspicious activity.
  • User accounts accessed from affected devices should be reset on a clean computer.
  • Your organisation adopts a holistic all-round approach to Cyber Security as advocated by the 10 Steps to Cyber Security.

It is possible to detect the proof of concept exploit using two methods:

  • Tools such as Sysmon can be utilised to detect abnormal processes being spawned by spoolsv.exe.
  • Audit logs can be configured to generate security events when a hard link is created in the System32\Tasks folder.

Last edited: 17 February 2020 12:49 pm