Zero-Day Advisory
Fortinet Discovers Microsoft Word RTF File Handling Memory Corruption Vulnerability
Summary
Fortinet's FortiGuard Labs has discovered a memory corruption vulnerability in Microsoft Word.
Microsoft Word is a word processor developed by Microsoft and it is one of the components of Microsoft Office suites.
The memory corruption vulnerability is caused by an Use-After-Free error. It exists because Microsoft Word improperly handles a specially crafted Rich Text File (RTF) document. The vulnerability can be triggered when bogus style sheet is used in the RTF document. As a result, it can lead to arbitrary code execution upon successful exploitation when the crafted document is opened using the vulnerable Microsoft Word.
Solutions
FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:MS.Office.RTF.Stylesheet.File.Handling.Use.After.Free
Released Jan 05, 2018
Users should apply the solution provided by Microsoft.
Additional Information
Fortinet reported the vulnerability to Microsoft on November 14, 2017.
Microsoft confirmed the vulnerability on December 12, 2017.
Microsoft patched the vulnerability on January 09, 2018.
References
Acknowledgement
This vulnerability was discovered by Wayne Low of Fortinet's FortiGuard Labs.