Javier Fernández-Sanguino Peña from the Debian Security Audit Project has discovered multiple insecure uses of temporary files that could lead to overwriting arbitrary files via a symlink attack.
For the stable distribution (woody) these problems have been fixed in version 21.8-3.
The unstable distribution (sid) does not contain this package.
We recommend that you upgrade your htmlheadline package.
MD5 checksums of the listed files are available in the original advisory.