Stefan Nordhausen has identified a local security hole in net-acct, a user-mode IP accounting daemon. Old and redundant code from some time way back in the past created a temporary file in an insecure fashion.
For the stable distribution (woody) this problem has been fixed in version 0.71-5woody1.
For the unstable distribution (sid) this problem has been fixed in version 0.71-7.
We recommend that you upgrade your net-acct package.
MD5 checksums of the listed files are available in the original advisory.