A vulnerability has been found and corrected in transmission:
Directory traversal vulnerability in libtransmission/metainfo.c in
Transmission 1.22, 1.34, 1.75, and 1.76 allows remote attackers to
overwrite arbitrary files via a .. (dot dot) in a pathname within a
.torrent file (CVE-2010-0012).
The updated packages have been patched to correct this issue...