What We Do
How we do it
Resources
SECURITY ADVISORIES
Sep 23, 2021
SolarMarker Malware Activity
THE THREAT eSentire has observed a recent and significant increase in SolarMarker infections delivered through drive-by download attacks. These attacks rely on social engineering techniques to persuade users to execute malware disguised as document templates. SolarMarker is a modular information-stealing malware; infections may result in the theft of sensitive data including user credentials.…
Read More
View all Advisories →
Company
ABOUT eSENTIRE
About Us
eSentire is The Authority in Managed Detection and Response Services, protecting the critical data and applications of 1000+ organizations in 70+ countries from known and unknown cyber threats. Founded in 2001, the company’s mission is to hunt, investigate and stop cyber threats before they become business disrupting events.
Read about how we got here
Leadership Work at eSentire
LATEST PRESS RELEASE
Aug 25, 2021
eSentire named a Leader in IDC MarketScape for U.S. Managed Detection and Response Services
August 26, 2021 – Waterloo, ON -  eSentire, recognized globally as the Authority in Managed Detection and Response (MDR), announced today that it has been named a Leader in the IDC MarketScape: U.S. Managed Detection and Response Services 2021 Vendor Assessment (doc #US48129921, August 2021). IDC defines the core services an MDR must provide as follows: reduced time for onboarding, 24/7…
Read More
Partners
PARTNER PROGRAM
Partners
Our award-winning partner program offers financial rewards, sales and marketing tools and personalized training. Accelerate your business and grow your revenue by offering our world-class Managed Detection and Response (MDR) services.
Learn about our Partner Program
Search
Resources
Security advisories — Jul 23, 2021

Windows Local Privilege Escalation Vulnerability - CVE-2021-36934

THE THREAT

Microsoft has announced a high severity vulnerability impacting multiple versions of the Windows 10 operating system. The vulnerability is tracked as CVE-2021-36934 and is alternatively referred to as HiveNightmare and SeriousSAM. It is a Local Privilege Escalation (LPE) vulnerability; exploitation may allow a previously authenticated threat actor the ability to escalate their privileges on a vulnerable device and potentially install programs, change or delete data, or create new user accounts. Microsoft has not released security patches for this vulnerability. Organizations are strongly recommended to apply the relevant mitigations until security patches are made available.

What we’re doing about it

What you should do about it

Additional information

HiveNightmare impacts all versions of Windows 10 since version 1809, released October 17th, 2017. Proof-of-Concept (PoC) exploit code for this vulnerability is publicly available, but currently only allows for Denial-of-Service (DoS) attacks. It is highly likely that threat actors will alter the PoC code and employ it in real world attacks in the immediate future. As exploitation requires previous compromise, organizations are recommended to ensure that an endpoint monitoring solution is widely deployed in order to identify threat actor initial access attempts. 

Mitigations from Microsoft:

  1. Restrict access to the contents of %windir%\system32\config
    1. Command Prompt (Run as administrator): icacls %windir%\system32\config\*.* /inheritance:e
    2. Windows PowerShell (Run as administrator): icacls $env:windir\system32\config\*.* /inheritance:e
  2. Delete Volume Shadow Copy Service (VSS) shadow copies
    1. Delete any System Restore points and Shadow volumes that existed prior to restricting access to %windir%\system32\config
    2. Create a new System Restore point (if desired) 

References: 
[1] https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-36934