Wilfried Goesgens discovered that WebCit, the web-based user interface for the Citadel groupware system, contains a format string vulnerability in the mini_calendar component, possibly allowing arbitrary code execution (CVE-2009-0364).
For the stable distribution (lenny), this problem has been fixed in version 7.37-dfsg-7.
For the unstable distribution (sid), this problem has been fixed in version 7.38b-dfsg-2.
We recommend that you upgrade your webcit packages.
MD5 checksums of the listed files are available in the original advisory.