Google photos will tag your photos automatically based on the metadata information such as geographic coordinates, date, etc.
The Photo metadata allows information to be traveled along with the image file that can be read by software, hardware, and end users.
By calculating the baseline time based on the trigger event, then researchers used the search query “photos of me from Iceland” and compared the result to the baseline.
If the query took a long time than the baseline time, then it will be assumed that query returned results matching to the photos in Iceland.
How the Attack Works
In order to make the attack works, first, the attacker needs to trick the user to open the malicious website at the time when the user logged into Google Photos. Imperva published a Video demonstration explaining the attack.
Once the malicious website is opened in the browser it silently generates requests to the Google Photos search endpoint and extracts answers to any query the attacker wants.
This process can be incremental, as the attacker can keep track of what has already been asked and continue from there the next time you visit one of his malicious websites, reads Imperva report.
The vulnerability was reported to Google by Imperva and the vulnerability has been patched now.