I'm also experiencing this behavior. After upgrading to lenny 5.0.5, `debsecan --suite lenny --only-fixed` lists these advisories, as well as many others (648 total):
CVE-2009-1300 apt (fixed, remotely exploitable, high urgency) CVE-2009-1358 apt (fixed, remotely exploitable, high urgency) CVE-2009-1300 apt-utils (fixed, remotely exploitable, high urgency) CVE-2009-1358 apt-utils (fixed, remotely exploitable, high urgency) Listing the details of the apt package: CVE-2009-1300 (fixed, remotely exploitable, high urgency) apt 0.7.20 does not check when the date command returns an "invalid ... installed: apt-utils 0.7.20.2+lenny2 (built from apt 0.7.20.2+lenny2) fixed in unstable: apt 0.7.21 (source package) fixed on branch: apt 0.6.46.4-0.1+etch1 (source package) fixed on branch: apt 0.7.20.2+lenny1 (source package) fixed on branch: apt 0.7.20.2+squeeze1 (source package) fixed on branch: apt 0.7.25.3 (source package) fix is available for the selected suite (lenny) So you can see that the vulnerability was fixed in apt version 0.7.20.2+lenny1. I have apt version 0.7.20.2+lenny2 and debsecan considers my version vulnerable, so I believe this is a bug in debsecan.