Fortinet Discovers Swisscom TVMediaHelper DLL Preloading Vulnerability
Summary
Fortinet's FortiGuard Labs has discovered a DLL preloading vulnerability in Swisscom's TVMediaHelper for Windows.
Swisscom's TVMediaHelper for Windows is a desktop application using which users can enjoy photos and music that they have shared on their computer (Windows PC) via Swisscom TV.
Swisscom's TVMediaHelper for Windows is susceptible to a DLL preloading vulnerability. The issue occurs when the application looks to load a DLL for execution and an attacker provides a malicious DLL to use instead. The application generally follows a specific search path to locate the DLL. The vulnerability can be exploited by a simple file write (or potentially an over-write) which results in a foreign DLL running under the context of the application.
Solutions
Users should remove the application from their system since it is a legacy application and no longer maintained by the vendor.
Timeline
Fortinet reported the vulnerability to Swisscom on June 15, 2017.
Swisscom confirmed the vulnerability on August 31, 2017.
Swisscom removed the vulnerable software on August 31, 2017.