The (1) mdb and (2) mdb-symbolreader scripts in mono-debugger 2.4.3, and other versions before 2.8.1, place a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse shared library in the current working directory.
https://bugzilla.novell.com/show_bug.cgi?id=647353
http://www.mono-project.com/Vulnerabilities#mono-debugger_Insecure_Use_of_LD_LIBRARY_PATH