Untrusted search path vulnerability in TortoiseSVN 1.6.10, Build 19898 and earlier allows local users, and possibly remote attackers, to execute arbitrary code and conduct DLL hijacking attacks via a Trojan horse dwmapi.dll that is located in the same folder as a file that is processed by Tortoise.  NOTE: this is only a vulnerability when a file extension is associated with TortoiseProc or TortoiseMerge, which is not the default.