Skype 3.6.0.248, and other versions before 3.8.0.139, uses a case-sensitive comparison when checking for dangerous extensions, which allows…

Skype 3.6.0.248, and other versions before 3.8.0.139, uses a case-sensitive comparison when checking for dangerous extensions, which allows user-assisted remote attackers to bypass warning dialogs and possibly execute arbitrary code via a file: URI with a dangerous extension that uses a different case.