Zero-Day Advisory
Fortinet Discovers Windows Font Library Memory Corruption Vulnerability
Summary
Fortinet's FortiGuard Labs has discovered a Memory Corruption vulnerability in Microsoft Windows Embedded OpenType font library.
The EOT font library allows compressed OpenType font to be embedded in various font formats. The vulnerable Windows font library is used by many applications ranging from Internet Explorer, Microsoft Office and other third party software that utilizes this font library. The font library exists in all version of Windows.
The Memory Corruption vulnerability exists when the Windows font library improperly handles specially crafted embedded fonts. An attacker who successfully exploited this vulnerability would gain code execution on the target system.
Solutions
FortiGuard Labs released the following FortiGate IPS signature which covers this specific vulnerability:MS.Windows.Express.Compressed.Fonts.Remote.Code.Execution
Released Aug 17, 2017
Users should apply the solution provided by Microsoft.
Additional Information
Fortinet reported the vulnerability to Microsoft on July 29, 2017.
Microsoft patched the vulnerability on August 8, 2017.
References
Acknowledgement
This vulnerability was discovered by Wayne Low of Fortinet's FortiGuard Labs.