The DataLoader::doStart function in dataloader.cpp in QGit 1.5.6 and other versions up to 2pre1 allows local users to overwrite arbitrary files and execute arbitrary code via a symlink attack on temporary files with predictable filenames.
Exploitability
AV:LAC:MAu:NImpact
C:CI:CA:C6.9/AV:L/AC:M/Au:N/C:C/I:C/A:C