What We Do
How we do it
Resources
TRU INTELLIGENCE CENTER
Our Threat Response Unit (TRU) publishes security advisories, blogs, reports, industry publications and webinars based on its original research and the insights driven through proactive threat hunts.
View Threat Intelligence Resources →
SECURITY ADVISORIES
Aug 17, 2022
Increase in Observations of Socgholish Malware
THE THREAT Starting in early August 2022 and continuing through the month, eSentire identified a significant increase in Socgholish (aka. FakeUpdates) malware incidents. Socgholish is a loader type…
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 1500+ organizations in 80+ 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
Sep 20, 2022
eSentire Recognized as Top Global MDR Provider by MSSP Alert, CrowdStrike and G2
Waterloo, ON - September 21, 2022 – eSentire, Inc., the Authority in Managed Detection and Response (MDR), celebrated multiple industry recognitions as the leading global MDR provider, over the last week: Named #9, and the top pure play MDR provider on MSSP Alert’s Top 250 MSSPs global rankingRecognized as the CrowdStrike 2022 Global MSSP Partner of the Year Earned G2’s industry-renowned status…
Read More
Partners
PARTNER PROGRAM
e3 Ecosystem
We provide sophisticated cybersecurity solutions for Managed Security Service Providers (MSSPs), Managed Service Providers (MSPs), and Value-Added Resellers (VARs). Find out why you should partner with eSentire, the Authority in Managed Detection and Response, today.
Learn more
ECOSYSTEM PARTNER RESOURCES
Apply to become an e3 ecosystem partner with eSentire, the Authority in Managed Detection and Response.
Login to the Partner Portal for resources and content for current partners.
Search
Resources
Security advisories — Apr 27, 2020

Microsoft Teams Vulnerability

1 minute read
Speak With A Security Expert Now

THE THREAT

On April 27th, 2020, researchers publicly announced a vulnerability affecting Microsoft Teams, which could be used to take over Microsoft Teams accounts [1]. Microsoft Teams desktop application and web browser version are both affected. There is currently no known public exploitation or Proof of Concept (POC) code, resulting in the current risk rating of Low. Microsoft issued a patch to fix the vulnerability on Apr 20, 2020 which has been automatically applied to all Microsoft Team clients.

What we’re doing about it

What you should do about it

Additional information

In order to exploit this vulnerability, threat actors need to first takeover a Microsoft Teams' subdomain, in order to host a file that potential victims can attempt to access. Researchers from CyberArk used a GIF to demonstrate the attack. The vulnerability itself resides in how the Microsoft Teams authenticator token is revealed when a resource is requested by the host. If an end user requests access to a file hosted on the compromised subdomain, the threat actor can capture the authentication token without alerting the end user.

The stolen authentication token can then be reused to gain the users "skypetoken". The "skypetoken" and authentication token can then be used in tandem by a threat actor to read or send messages, create groups, and add or remove users in the context of the compromised user. The vulnerability raised serious concerns as threat actors could create wormable exploits that could automatically spread through vulnerable systems.

The criticality of this vulnerability is considered Low as Microsoft Teams has already automatically applied the security patch across its user base. Additionally, Microsoft has addressed the issue that was used by researchers to takeover the Microsoft subdomains.

References:

[1] https://www.cyberark.com/threat-research-blog/beware-of-the-gif-account-takeover-vulnerability-in-microsoft-teams/

[2] https://docs.microsoft.com/en-us/microsoftteams/teams-client-update

Join 100,000+ Security Leaders

Get notified when there's a new security advisory, and receive the latest news, intel and helpful tools & assets. You can unsubscribe anytime.

By clicking the button below I confirm that I have read and agree to the eSentire privacy policy.

View Most Recent Blogs