WhatsApp groups appear when searching through Google again, and as a result, anyone can discover a private WhatsApp group and join it after searching through Google.
This was first discovered in 2019 and appears to have been fixed last year after turning public.
Another old issue, which also appears to have been fixed, but has reappeared, is that user accounts appear through search results.
Because of this problem, people can display their phone numbers and profile pictures with a simple Google search.
By allowing group chat invitations to be indexed, WhatsApp provides many private groups across the web where anyone can access their links using a simple Google search query.
The person who finds these links can join groups and can also see the participants and their phone numbers with posts being published within these groups.
Cybersecurity researcher Rajshekhar Rajaharia reported indexing group chat invitations in WhatsApp via Google.
Indexing appears to have started again recently, and there were over 1,500 group invite links available in search results at the time of writing.
Some of the links that were indexed by Google lead to WhatsApp groups to share pornography, and in a few other cases, there were links to WhatsApp groups dedicated to a specific community or interest.
And people who have not been invited can easily join groups using links.
It is noteworthy that this is not the first time that this problem has occurred, as in November 2019, the WhatsApp group chat invitations were found in Google search results.
The issue was reported to Facebook by a security researcher, although it was resolved shortly after it was covered by several news outlets in February of last year.
Engineer Jane Manchun Wong reported that WhatsApp fixed the group chat indexing issue by adding the meta tag noindex to invite links, however recent links include the noindex meta tag.
It seems that the group chat links that were revealed in 2019 are not visible via Google, so this may be a different problem that leads to similar results, or a change that inadvertently led to the emergence of the old problem.
The security researcher said: The chat.whatsapp.com subdomain did not include a robots.txt file that indexes group chat invitations across Google and other search engines.
Typically, web developers use robots.txt to tell search engine programs which pages or files they can index and which they should not index.
In addition to the group invite links, it appears that WhatsApp has allowed Google again to index user accounts, allowing anyone to chat with a user or look at their profile picture.
WhatsApp user profiles can be accessed again via Google, as the search engine has indexed more than 5,000 profile links.
Some links also lead to users who have allowed anyone within the messaging app to see their profile pictures and statuses.