A security feature bypass vulnerability exists in Dynamics On Premise. An attacker who exploited the vulnerability could send attachment types that are blocked by the email attachment system.
To exploit the vulnerability, an attacker would need to capture and edit the POST request to include a special character in the extension.
The update addresses the vulnerability by blocking files with the special character in the file extension.
## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Microsoft | Microsoft Dynamics 365 (on-premises) version 8.2 | | [KB4494412](https://patchblox.com/security/data/fix/microsoft/kb4494412.md) | May 14, 2019 | | Microsoft | Microsoft Dynamics 365 (on-premises) version 9.0 | | [KB4498363](https://patchblox.com/security/data/fix/microsoft/kb4498363.md) | May 14, 2019 | | Microsoft | Microsoft Dynamics CRM 2015 (on-premises) version 7.0 | | [KB4499386](https://patchblox.com/security/data/fix/microsoft/kb4499386.md) | May 14, 2019 | --- Data as of 2026-11-07T18:46:35Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.