Microsoft Blocks Flash and Silverlight in Office 365 Documents

Microsoft recently announced a policy update that will limit the use of Flash, Shockwave, and Silverlight controls in Office 365. As Tom Gallagher, manager of the Microsoft Office Security Engineering team, points out, the content will be blocked from activating in Office. Specifically, the software giant stated that because Flash, Shockwave, and Silverlight are still used for vulnerability activities against Office users, and the user base of these controls is shrinking, restrictions will be imposed.

By the end of 2020, Adobe will also end its support for Flash. Silverlight also expects to reach the end of support in 2021. Technically speaking, Flash and Silverlight content in Office 365 documents will no longer be enabled once this decision takes effect. This policy does not affect Office 2016, Office2013, or Office 2010.

Microsoft said that this change does not include the activation of these controls outside of the Office process. For example, inserting Flash video into a document by inserting an online video feature. Microsoft will still allow customers to open controls based on their true needs, and the company provides specific guidance in this area. However, this is not recommended because this decision involves multiple security factors and preventing Flash can help prevent some system-specific attacks.