+++ This bug was initially created as a clone of Bug #190923 +++ awstats < 6.6 has reportedly an arbitrary code execution vulnerability, fixed in upstream 6.6. No CVE id yet (I've mailed them), but here's more info: http://www.vuxml.org/freebsd/2df297a2-dc74-11da-a22b-000c6ec775d9.html
Awstats 6.6 is still in beta and did not work for me (update gave "Use of uninitialized value in substitution (s///) at ..."), so I backported the fix from CVS instead (it's a two-liner). FC-5 and FC-4 versions building, devel is updated to 6.6 and I'll keep it updated when a new beta arrives.
It appears that this is not fixed; the problem is in the unsanitized "migrate" query string parameter.
Fixed, see bug 190923 for details