JVN#91151862: Multiple Microsoft Windows applications and installers may insecurely load Dynamic Link Libraries

Multiple Windows applications and installers provided by Microsoft contain an issue with the DLL search path, which may lead to insecurely loading Dynamic Link Libraries in the same directory where applications and/or installers reside (CWE-427).
Microsoft states that the root cause of this vulnerability is “Application Directory (App Dir) DLL planting” and attacks exploiting this vulnerability are limited, thus there is no plan to release any security updates to address this issue.

For details, refer to “Application Directory (App Dir) DLL planting” released by Microsoft.

Impact

If a crafted DLL file is in the same directory where the vulnerable applicaion and/or installer resides, arbitrary code may be executed with the privilege of the user invoking the application or installer.

Solution

Apply Workaround

• Make sure to allow that the system directories are writable only by administrators, which is the Windows’ initial configuration.
• Operate Windows PCs with a standard user (non-administrator) account. Administrator accounts should be used only when necessary.
• When invoking an installer, make sure there are no unrelated files in the same directory where the installer resides. It is strongly recommended to copy the installer into a newly created directory and invoke it from that directory.
• Make sure there are no untrusted files in the directory where the application is installed.
• If your organization uses shared directories to place installers for organizational operations, make sure that the shared directory is set read-only for non-administrative users.
  Note that some applications including Microsoft OneDrive may be installed in user directories, not in system directories.
  Apply respective workarounds in accordance with how respective applications are installed and used.

Products Affected

• Microsoft OneDrive - CVE-2018-0592
• The installer of Microsoft OneDrive - CVE-2018-0593
• Skype for Windows - CVE-2018-0594
• The installer of Skype for Windows - CVE-2018-0595
• The installer of Visual Studio Community - CVE-2018-0596
• The installer of Visual Studio Code - CVE-2018-0597