# SpamAssassin 2010 Bug

I use [SpamAssassin](https://spamassassin.apache.org/) to filter the spam out of
my incoming email. Last night I noticed that a legitimate email had a
particularly high spam score. On further investigation I found that a rule named
FH_DATE_PAST_20XX was triggering:

```text
* 3.2 FH_DATE_PAST_20XX The date is grossly in the future
```

I checked the Date header of the email and it looked totally fine to me. It had
just changed from the year 2009 to the year 2010. Could that be a coincidence? A
quick look in /usr/share/spamassassin/72_active.cf turned up the rule:

```text
header FH_DATE_PAST_20XX Date =~ /20[1-9][0-9]/ [if-unset: 2006]
```

Oops. That regex matches on any year between 2010 and 2099\. I googled for the
rule and came across this:

[http://wiki.apache.org/spamassassin/Rules/FH_DATE_PAST_20XX](http://wiki.apache.org/spamassassin/Rules/FH_DATE_PAST_20XX)

In the comments it mentioned the problem which I found: Note: the current rule
in 3.2 will start matching legitimate dates from 2010-01-01. See issue
[#5852](https://issues.apache.org/SpamAssassin/show_bug.cgi?id=5852). Looking
at issue [5852](https://issues.apache.org/SpamAssassin/show_bug.cgi?id=5852),
the problem was first identified on 2008-Nov-05 and was fixed in CVS on
2009-Jun-30. I'm using the standard stable Debian package which doesn't contain
this fix yet so I had to stick the following in my local.cf file to apply a
score of 0 to it:

```text
score FH_DATE_PAST_20XX 0.0
```

I think a lot of systems will be experiencing false positives on their ham
because of this at the moment. It is a particularly high scoring rule
considering that the default threshold is 5.0.

As I understand it, rules aren't distributed with SpamAssassin as of the next
version (3.3) so hopefully problems like this wont happen in future. The fix
which was supplied for this problem five months ago was to update the regex so
it matches 2020-2099 instead.

You can read the thread I started about this issue on the SpamAssassin users
list
[here](https://mail-archives.apache.org/mod_mbox/spamassassin-users/201001.mbox/thread?0).
It'™s the one started at Fri, 01 Jan 2010 00:57:37 GMT with the subject line
"FH_DATE_PAST_20XX"