Jeroen van Wolffelaar discovered a problem in lintian, the Debian package checker. The program removes the working directory even if it wasn't created at program start, removing an unrelated file or directory a malicious user inserted via a symlink attack.
For the stable distribution (woody) this problem has been fixed in version 188.8.131.52.
For the unstable distribution (sid) this problem has been fixed in version 1.23.6.
We recommend that you upgrade your lintian package.