Unsafe Expressions - Macro Security In Access 2003

Author: Garry Robinson from GR-FX, November 2003

THIS PAGE IS IN DEVELOPMENT BUT MAY HELP SOMEONE

To Do - Access 2000 Developers Upwards

Developers will need to download the following service pack. This will change the version of Jet 4 that you are using with Access 2000, 2002, 2003. You should start explaining to you customers that they should upgrade if they intend installing Access 2003 before Mid 2004. Otherwise, they encounter more issues than they need to. Find out more and download from the following Microsoft Knowledge Base Article - 829558

Otherwise head to windowsupdate.microsoft.com
Scan for updates
Pick the operating system list. (It is a non essential download)
Find Update for Jet 4.0 Service Pack 8 (KB829558) and click Add
Click Review and Install updates
Click Install Now

When you have finished, the file c:\windows\system32\msjet40.dll should have a version property value of 4.0.8015.0

When you install Access 2003 on a computer, it is very likely that you are going to enocunter the following screen. the following page shows you what happens when you open the Office 2003 Northwind database that came straight from the Office CD Rom. Why you cannot trust this database is beyond me and why the database came without being signed by Microsoft is bissare. Anyway it makes an interesting technology read.

Figure 1

If you read this form, you will probably guess that you need to click either Yes or No but what for is hard to work out. If you first click the Hide Help button, it is easier to work out that you are meant to confirm whether you want to open the database or not. If you click No, it means that you are not ready for these unsafe expresssions, whatever they are and you don;t want . If you are to follow the links to unsafe expressions, you need to work hard to find some useful help. The page that this help tries to direct you is here. The Open in Help window help has a link that leads to a dead end, so don't bother with that one.

Its Time To Regroup

At this stage I suggest that you click No and have a read about a few topics by going to this page.

Read about Microsoft Jet Expression Service sandbox mode

Charging On

I know, you charged on by clicking the Yes button in Figure 1 and you then were greeted with the next wonderfully inviting screen. Imagine if you were a user and they were greeted by this the first time that they opened your database. Image worse still if they were greeted by this everytime that they opened your database. Anyway in this instance, the More Info button brings up some quite useful help in the help window so you may want to read all that first.

Figure 2 - Security Warning Opening a Database

To continue on, you must Click the Open button. That then opens the Northwind database and all seems pretty good. You then go to open the same database again after making no changes to the code and guess what, you run into all the same prompts as shown above. Cleary you would never want your user to go through all this nonsense, well at least not without an explanation.

Turning Off Your Macro Security - Setting To Low Level

Havign been through this exercise before with the beta versions of Access 2003, I then went to the menu Tools ~ Macros to find the Security. The only thing is that it wasn't there this time. Maybe this is becuase I haven;t installed Jet 4 Service Pack 8 but I am not sure. So I searched the help and guess what, adding the Security option to the macro menu was very long winded. The instructions from the help file follow and you can see the whole thing if click on the image in Figure 3. This image takes the whole screen to fit all the cascading windows on the page.

 
Figure 3 -

I still can't see the Security command under the Macro menu

On the Tools menu, click Customize, and then click the Commands tab.

Click Rearrange Commands, select Menu Bar, and in the Menu Bar box, click Tools | Macro.

In the Controls section, click Add.

The Add command dialog box will appear.

In the Categories box, click Tools, and then in the Commands box, click Security.
The Security command will appear in the Controls box.

Use the Move Up and Move Down buttons to position the Security command where you want.
If you'd like to position the Security command in its own group (between horizontal lines), with Security selected, click Modify Selection and click Begin a Group. Select the menu item below the Security command, and repeat.

Click Close twice.

Turning Off The Macro Security Warnings

Now that you hopefully have the macro security menu option visible, you can turn off the macro security as follows

Go to the menu Tools ~ Macros ~ Security and the dialog box displayed in Figure 4 will be displayed. Now select the Low Security Level and all the prompts will disapear. Possibly though a macro virus will be run from your database.

Figure 4 - Macro Security Levels.

What Happens When You Select Low Security

When you select the Low security setting, you would think that the complications for you (and your users) would be over. Unfortunately not, there is more. There is the ambiguos question about unsafe expressions. The answer to this lies not in choosing Yes or No but in testing your application to see if it has any unsafe expressions or not. If it doesn't, then you can pretend to be a security expert and advise your client that it is OK to use your database whilst selecting No to this prompt. What this prompt is saying is that if you Click Yes, Sandbox mode will be turned off and of you click no it will be turned on.

Figure 5

Problems With Wizards

If You Leave The Sandbox On (answer No to msgbox in Figure 5) And Are Running Jet 4.7, you will encounter an error like that shown in Figure 6.

Figure 6 - Sandbox mode error with Jet 4.7.

Now if you also happen to be running Access 2002 on your computer, you will suddenly run into the following error when running wizards

Figure 7 - Access 2002 Error caused by Sandbox mode.

If you are using Access 2002, you can simulate this by searching the registry for SandboxMode and making the value of the key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Jet\4.0\Engines\SandboxMode = 3

Rememember to reset it back to 2 when you have finished your testing.

Macro Security In Access 2003
http://office.microsoft.com/assistance/preview.aspx?AssetID=HP010446071033&CTT=4&Origin=CH010411431033

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