NOTE: Battle Blog 1.50 now addresses these vulnerabilities. There is no reason to apply these fixes manually unless you are not able to upgrade.
Hackers have been busy pounding away at little ol' Battle Blog. Honestly, if I had to pay for this kind of research it would easily be a triple digit figure to some application security company. Say what you will about the Cairo hackers and their minions of low-grade vandals, they're dirt cheap for the information they yield. For absolutely free, they've uncovered two big holes.
First, they have discovered that the upload form is not protected from unathenticated access and does not necessarily prevent the upload of certain files, like PHP scripts, that could actually be triggered to affect the hosting machine in all kinds of ugly ways. Not that I know how they could be triggered, but I have evidence they have an idea, and, whatever those ideas are, probably worked against other websites. In my case for whatever lucky reason, the scripts didn't execute as tried.
Second, they've discovered that the comments section wasn't sanitizing properly. There is an entire function devoted to this in the Battle Blog code, but it was apparently disabled during one of the releases. This left the comment page vulnerable to some simple meta tag redirections. Someone could post a few lines of HTML as a comment that, in turn, causes the visitor landing on the comment page to be cast elsewhere on the web. It can be pretty dramatic and scary - though, so far, the hackers have deposited folks to seemingly benign web places that do little more than taunt or teach.
Fixing the Comment Vulnerabilities
To fix this is relatively easy. Open commentpreview.asp which is located in the Battle Blog root directory. Near the top of this page is where comments are definitevely handled and altered for later processing even though it's just a preview page.
In this page, insert the following line of codes at or about line # 13:
14> ' Execute Comment Cleanup
15> CommentComment=RemoveHTML(CommentComment)
When you're finished, your final page should look like:

Now be sure to save the work and you should be good to go.
File Upload Vulnerability
The next issue you should probably address independently (until the next release) involves Battle Blog's upload form. It too allows bad things to be uploaded in the sense that it doesn't limit uploads to JPEGs or GIFs. However, that's not so much the problem as much as the fact that the upload form can be accessed independently of the administrator control panel. As long as someone can guess the location of uploadform.asp, they can load it in their web browser and begin uploading files to your server or hosting account without being authorized as a Battle Blog administrator or editor. Of course, with Battle Blog being open source and all, no one really has to "guess".
So, for this fix, a few lines of code need to be pasted into the top of uploadform.asp to include it in Battle Blog's standard authentication scheme. This will not fix the problem of any sort of file being uploaded, which is debatable as a problem (maybe you actually do need to load PDFs or zip files in your particular case), but it will lock the form down so that only you and other approved folks can use it.
Here's what to do:
Open uploadform.asp which is located in the admin subfolder.
Look for an existing include reference to a config.asp file and delete it (don't worry, it will be replaced in a moment). Just delete the entire line which is probably line # 7 if you haven't altered it in any way.
In its place, insert these lines of code. The reference to the config.asp will return as part of this paste. However, so will references to other includes that control access to the form.
When you're done with this operation, your uploadform.asp will look like:

Now be sure to save your change. At this point your uploadform.asp will only be available after you log into the Battle Blog administrator panel.
Both of these fixes have stopped the specific vandalizations and attack attempts at this website and so there is a reasonable degree of expectation they will at yours. But remember, I'm not some ASP expert and god only knows if these fixes by themselves will be enough. I am sure my crack team of hackers will be more than happy to help determine so. If you are a programmer who spots ways to improve these fixes, be sure to let me know ASAP.