Exploiting Microsoft Teams Impersonation and Spoofing Vulner...

[carlospolop]

🤖 Automated Content Update

This PR was automatically generated by the HackTricks News Bot based on a technical blog post.

📝 Source Information

• Blog URL: https://research.checkpoint.com/2025/microsoft-teams-impersonation-and-spoofing-vulnerabilities-exposed/
• Blog Title: Exploiting Microsoft Teams: Impersonation and Spoofing Vulnerabilities Exposed
• Suggested Section: Phishing Methodology > Messaging/Collaboration Platforms > Microsoft Teams Impersonation & Notification Spoofing (CVE-2024-38197)

🎯 Content Summary

Post focus
Check Point Research dissected four Microsoft Teams impersonation/spoofing vulnerabilities that let external guests or malicious insiders manipulate trust signals across chats, notifications, and calls. Microsoft addressed all issues by October 2025; the notification-spoofing bug is tracked as CVE-2024-38197 (initially noted in Teams for iOS). Impact spans executive impersonation, BEC-style fraud, malware delivery, misinformation, privacy breaches, and disruption of ...

🔧 Technical Details

Unlabeled message edits by reusing clientmessageid: If a chat system correlates messages by a client-supplied ID, send a new message reusing the original clientmessageid (e.g., 2711247313308716623) with different content. The UI may render the replacement without an "Edited" marker. Use response metadata like OriginalArrivalTime to reference or time-align edits.

Notification impersonation via display-name fields: Where notifications render a sender string sourced from payload fields (e.g., imdisplayname or similar "from" attributes), set it to a high-trust identity (e.g., “CEO”). Clients that don’t canonicalize/validate this will show a forged sender, driving high click-through and compliance (CVE-2024-38197).

1:1 chat relabeling by abusing group-topic endpoints: If a platform exposes a thread-topic property endpoint for group chats (e.g., PUT .../threads/<ConversationID>/pr...

🤖 Agent Actions

I analyzed the blog and HackTricks repo, searched for existing content on Microsoft Teams/message-based phishing techniques, and confirmed there was no dedicated coverage. I created a new concise, highly technical page under Phishing Methodology and linked it from the Phishing Methodology README.

What I added/changed:

• New page: src/generic-methodologies-and-resources/phishing-methodology/microsoft-teams-impersonation-spoofing.md

  • Covers four techniques with precise fields/endpoints and example payloads:
    • Unlabeled edits via clientmessageid reuse
    • Notification sender spoofing (CVE-2024-38197) via imdisplayname
    • 1:1 chat relabeling via topic API (PUT /api/chatsvc/.../properties?name=topic)
    • Caller ID spoofing in calls via POST /api/v2/epconv using participants[].displayName
  • Includes identifiers and message parameters (content, messagetype, clientmessageid, imdisplayname, OriginalArrivalTime; user IDs like 8:orgid:...)
  • Detection ideas and concise defensive guidance
  • References section with the Check Point blog URL
  • Proper HackTricks banner includes

• Linked the new page from Phishing Methodology README:

  • Added a “Messaging / Collaboration Platforms” section with a {{#ref}} link to the new page in:
    src/generic-methodologies-and-resources/phishing-methodology/README.md

No other sections were modified and no redundant content was added.

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This PR was automatically created by the HackTricks Feed Bot. Please review the changes carefully before merging.

📚 Repository Maintenance

• MD files processed: 908
• MD files fixed: 1

All .md files have been checked for proper formatting (headers, includes, etc.).

[carlospolop]

🔗 Additional Context

Original Blog Post: https://research.checkpoint.com/2025/microsoft-teams-impersonation-and-spoofing-vulnerabilities-exposed/

Content Categories: Based on the analysis, this content was categorized under "Phishing Methodology > Messaging/Collaboration Platforms > Microsoft Teams Impersonation & Notification Spoofing (CVE-2024-38197)".

Repository Maintenance:

• MD Files Formatting: 908 files processed (1 files fixed)

Review Notes:

• This content was automatically processed and may require human review for accuracy
• Check that the placement within the repository structure is appropriate
• Verify that all technical details are correct and up-to-date
• All .md files have been checked for proper formatting (headers, includes, etc.)

Bot Version: HackTricks News Bot v1.0