It is most likely an old bug that has been fixed and upgrading would likely solve it.
If your site is on the internet, I strongly urge you to upgrade, it is not safe to run an old version like that and it is only a matter of time before your site could be hacked. This is really not something to take lightly if your site has any importance. I would not sleep well at night if I were running a site with that version.
If it is an intranet on a private network you can probably get away with waiting. If not I think you should give it more urgency.
In the meantime I would make sure you have a very good backup routine so that in the event your site does get hacked you have a way to recover.