Facebook Google Plus Twitter LinkedIn YouTube RSS Menu Search Resource - BlogResource - WebinarResource - ReportResource - Eventicons_066 icons_067icons_068icons_069icons_070

Tenable 部落格


Microsoft Teams: Vulnerability in Microsoft Power Apps Service Allows Theft of Emails, Files and More

A flaw in Microsoft Power Apps could allow attackers to steal emails, Teams messages and OneDrive files.


Microsoft recently patched a vulnerability in Microsoft Teams, a business communication platform that has surged in popularity with the shift to a remote workforce, recording 145 million daily active users in April 2021. The vulnerability, which was discovered by Tenable Zero-day Researcher Evan Grant, could allow an attacker to take control of an end-user’s account. This could grant the attacker access to the victim’s chat history, the ability to read and send emails on the victim’s behalf, and access files in their OneDrive storage.


Microsoft Teams has a default feature that allows users to launch applications as a tab within any team they belong to. Organizations using Office 365 or Microsoft Teams with a Business Basic license or higher can also launch Microsoft Power Apps within these tabs.

Tenable discovered that content loaded into these Power Apps tabs was governed by an improperly anchored regular expression. That is, the validation mechanism used to confirm that the content in the tab comes from a trusted source only verifies that a given URL begins with “https://make.powerapps.com” and does not validate any further. This means an attacker can simply create a subdomain of “make.powerapps.com” for any domain they control, such as https://make.powerapps.com.fakecorp.ca, which allows them to load untrusted content into a Power Apps tab.

The severity of this vulnerability is amplified by the permissions granted to Microsoft Power Apps within Microsoft Teams. Successful exploitation of this flaw allows attackers to take control of any users that access the malicious tab. This includes reading the victim users’ group messages within Teams, accessing the users’ email and OneDrive storage, and more.

Proof of concept

As this flaw is a server side vulnerability, Microsoft fixed the issue without any user action required. Because the issue has been patched, a proof-of-concept will not be released, however detailed information and a full analysis for this issue can be found on the Tenable Techblog. The following video demonstration shows how the flaw could have been abused:

Vendor response

Through our vulnerability disclosure policy, Tenable worked with Microsoft to review and address our findings. For details on the disclosure timeline, please refer to our corresponding Tenable Research Advisory.


Microsoft implemented a solution to address this issue — no action is required from end-users or organizations.


加入 Tenable Community 的 Tenable 安全回應團隊

深入瞭解 Tenable,這是用於全面管理新型攻擊破綻的首創 Cyber Exposure 平台。

Get a free 30-day trial of Tenable.io Vulnerability Management.



輸入您的電子郵件地址,以便收到最新 cyber exposure 警示。

選擇 Tenable.io

免費試用 30 天

享受現代、雲端型的弱點管理平台,能夠以無與倫比的準確性查看和追蹤所有資產。 立即註冊。

立即購買 Tenable.io

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

65 項資產



免費試用 Nessus Professional

免費試用 7 天

Nessus® 是現今市場上功能最全面的弱點掃描工具。Nessus Professional 能協助自動化弱點掃描程序、節省您達到合規性的時間並讓您的 IT 團隊合作。

購買 Nessus Professional

Nessus® 是現今市場上功能最全面的弱點掃描工具。Nessus Professional 能協助自動化弱點掃描程序、節省您達到合規性的時間並讓您的 IT 團隊合作。

購買多年期授權,節省更多。新增 365 天全年無休 24 小時全天候可使用電話、社群及對談的進階支援。完整詳情請見此處。

試用 Tenable.io Web Application Scanning

免費試用 30 天

享受我們專為現代應用程式而設計,屬於 Tenable.io 平台一部分的最新 Web 應用程式掃描產品的所有功能。不需耗費大量人力或中斷重要 Web 應用程式,即可高度準確且安全地掃描您整個線上產品系列中是否含有任何弱點。 立即註冊。

購買 Tenable.io Web Application Scanning

享受現代、雲端型的弱點管理平台,使您能夠以無與倫比的準確性查看和追蹤所有資產。 立即訂閱一年。

5 個 FQDN



試用 Tenable.io Container Security

免費試用 30 天

享受整合至弱點管理平台中的唯一容器安全產品的完整功能。監控容器映像中是否有弱點、惡意軟體及政策違規的情形。與持續整合和持續部署 (CI/CD) 系統整合,以支援 DevOps 作法、加強安全性並支援企業政策合規性。

購買 Tenable.io Container Security

Tenable.io Container Security 整合了建置程序,能提供包含弱點、惡意軟體和政策違規等容器影像安全性的能見度,讓您無縫並安全地啟用 DevOps 流程。

取得 Tenable.sc 產品示範

請填寫以下表格並附上您的聯絡資訊,我們的業務代表將盡快與您聯絡,以安排產品示範。您也可以附上簡短註解 (字元上限為 255 個)。請注意,標示星號 (*) 的欄位是必填欄位。

試用 Tenable Lumin

免費試用 30 天

透過 Tenable Lumin,能夠以視覺方式呈現 Cyber Exposure 並加以探索,長期追蹤風險降低狀況,以及對照同業進行指標分析。

購買 Tenable Lumin

聯絡業務代表,瞭解 Lumin 如何協助您獲得整個企業的深入洞見,並管理網路風險。

申請 Tenable.ot 產品示範



持續偵測與回應 Active Directory 攻擊。 無需代理程式、無需特殊權限。提供内部部署和雲端兩種選擇。