CVE-2019-0604

A remote code execution vulnerability exists in Microsoft SharePoint when the software fails to check the source markup of an application package, aka ‘Microsoft SharePoint Remote Code Execution Vulnerability’. This CVE ID is unique from CVE-2019-0594.

Recent assessments:

zeroSteiner at March 20, 2020 1:46pm UTC reported:

A .NET deserialization vulnerability exists within SharePoint that can be exploited remotely. The vulnerability was actively being exploited in the wild around the May 2019 time frame. Per the ZDI Advisory the vulnerability is due to a lack of validation on user supplied data to an encoder class which can be leveraged to deserialize attacker-supplied data resulting in remote code execution.

Per the Microsoft advisory:

> Exploitation of this vulnerability requires that a user uploads a specially crafted SharePoint application package to an affected version of SharePoint.

A public PoC has been released.

The initial vulnerability is triggered via an HTTP POST request to /_layouts/15/Picker.aspx?PickerDialogType=.

ccondon-r7 at August 31, 2020 2:18pm UTC reported:

A .NET deserialization vulnerability exists within SharePoint that can be exploited remotely. The vulnerability was actively being exploited in the wild around the May 2019 time frame. Per the ZDI Advisory the vulnerability is due to a lack of validation on user supplied data to an encoder class which can be leveraged to deserialize attacker-supplied data resulting in remote code execution.

Per the Microsoft advisory:

> Exploitation of this vulnerability requires that a user uploads a specially crafted SharePoint application package to an affected version of SharePoint.

A public PoC has been released.

The initial vulnerability is triggered via an HTTP POST request to /_layouts/15/Picker.aspx?PickerDialogType=.

hrbrmstr at May 12, 2020 7:48pm UTC reported:

A .NET deserialization vulnerability exists within SharePoint that can be exploited remotely. The vulnerability was actively being exploited in the wild around the May 2019 time frame. Per the ZDI Advisory the vulnerability is due to a lack of validation on user supplied data to an encoder class which can be leveraged to deserialize attacker-supplied data resulting in remote code execution.

Per the Microsoft advisory:

> Exploitation of this vulnerability requires that a user uploads a specially crafted SharePoint application package to an affected version of SharePoint.

A public PoC has been released.

The initial vulnerability is triggered via an HTTP POST request to /_layouts/15/Picker.aspx?PickerDialogType=.

Assessed Attacker Value: 5
Assessed Attacker Value: 5Assessed Attacker Value: 4