We’ve been amazed and dismayed to discover a privacy gap in Microsoft Office. A common situation that Microsoft should be aware of but has done nothing to fix or warn customers about.
The problem is with images inserted into Office documents (Word, Excel, PowerPoint). The image ‘meta-data’ including GPS coordinates is retained with the inserted image.
Anyone getting that document can not only see the picture but also find out where it was taken, when and even the camera used!
A photo of your child or pet can also reveal where you live. Photos of an item for sale can unwittingly disclose your home address. For many people, that’s information they’d prefer to keep private. It’s been an issue on social media for many years with celebrities and even ISIS leaders affected. This was well-known at least 5 years ago yet Microsoft has taken no action.
Where’s it hiding?
Photos (JPG, TIFF and various RAW formats) have extra information hidden in them called ‘meta-data’. There are various formats for this extra info, IPTC, XMP and the most common EXIF.
You can see the EXIF details of any photo in Windows. Right-click on an image, choose Properties then Details. Here’s an example showing some of the details available (date taken and date modified aren’t shown due to space limits).
As you can see, the GPS co-ordinates of the photo are shown. Some cameras and smartphones will add the country and city name too. (to save our curious readers some time; the co-ords above are for the Arc de Triomphe in Paris.)
When you insert an image from a file into an Office document the entire image, including the location details, are included in the document.
Anyone receiving the Office document can access the original image and access the extra details.
Many years ago there was a little uproar when people discovered how much ‘meta-data’ there is in Office document and how damaging that can be.
Microsoft’s first response was to release an interim ‘clean up’ tool for Office 2003/XP. An ‘Inspect Document’ feature is in Office 2007 and later editions.
The tool ‘Inspects for hidden metadata or personal information’ in the document. As we’ve seen, the tool doesn’t do that completely even though Content addins and embedded documents are checked.
The issue of image metadata has been known for many years and at least two major releases of Office. In that time, Microsoft could have taken some action, even if it was to alert customers about the potential privacy issues.
Instead customers may be mislead into thinking that ‘Inspect Document’ gives them better protection than it really does.
How to workaround this and keep your image location and meta-data free?
Remove EXIF data before insertion
Before inserting the image, check the meta-data (right-click on the image, Properties | Details). Choose ‘Remove Properties and Personal Information’. Most likely you’ll want to do this for a copy of the image that will be inserted into the document. Keep the original image with all the additional properties.
Choose from making a copy of the image with all properties removed or selectively removing properties from the current file. If you choose the latter option, make sure you have a separate copy of the original image with all the meta-data in place.
There are many other EXIF view/edit programs out there. Most image editors will let you change the meta-data as well. GeoSetter is a great tool for managing EXIF data, especially location info.
Compress the image in Office
In all our tests, compressing the image size within Office also removes the meta-data. Presumably because the entire image has to be re-written within the document.
To do that, select the image, choose Picture Tools | Format | Compress then make some change to the current target output. Most likely to Email or Screen resolution.
You can do this for the selected image or all images in the document.
Note: cropping an image within Office does NOT remove the image meta-data unless you then use the ‘Delete cropped areas of pictures’ option shown above. Cropping an image in Office only keeps the original picture plus new boundaries to display. ‘Delete cropped areas …’ forces the image to be rewritten within the document.