Application Security · Privacy
Meta Muse flaw exposed private conversations through share links
A design flaw in Meta's Muse AI assistant let anyone find thousands of shared conversations, exposing sensitive personal and business details. Meta has suspended the sharing feature while it reviews the issue.
Ross GrantUpdated 2 min read
The short version
Meta's Muse AI assistant had a flaw that made private conversations shared by users easy to find online. Security researchers found thousands of these shared links, some containing sensitive business or personal details. Meta has now suspended the sharing feature while it fixes the problem. If you shared anything sensitive using Muse, it may have been exposed.
By the numbers
- 6,800Muse share links found by researchersArs Technica
- dozensEmployees listed in a single exposed vacation calendarArs Technica
What happened?
A design flaw in Meta's Muse AI assistant made it possible for anyone to find and access thousands of shared conversations, exposing sensitive personal and business information. Security researchers discovered the issue and reported it to Meta. The company has suspended the sharing feature while it investigates.
What was taken
Researchers from security firm Claroc found that over 6,800 shared conversations from Meta's Muse AI assistant could be accessed by anyone who discovered the share links. After opening a sample, they found sensitive information such as:
- Notes for a confidential executive-search call, including internal contacts and meeting times
- A marketing company's internal revenue review marked for its CEO
- A small-business owner's loan application with the requested amount
- A to-do list with a bank fraud alert, partial account number, and transaction details
- A real-estate investor's internal performance report with property addresses and financial figures
- A workplace's full-year staff vacation calendar listing dozens of employees
These details were not intended to be public, but the design of the sharing feature made them easy to find [Ars Technica (opens in a new tab)][Wired (opens in a new tab)].
How the flaw works
Muse allowed users to share conversations by generating a unique web link. Normally, such links are hard to guess because they include a long random string. However, Muse's links also included the conversation title in the subdomain (for example, loan-application-draft-xxxx.cf.metaaiusercontent.com).
This design meant that anyone could use passive DNS search services to find these links. Passive DNS is a system that collects records of domain name lookups. When someone clicks a share link, the DNS request is logged and can be searched later. Because the conversation title was part of the subdomain, it was easy for researchers to enumerate and identify links containing sensitive information.
Claroc called these "GhostShares": pages that anyone could find and open, even if they were never sent the link.
The response
Meta said it has suspended the sharing feature while it reviews the issue and considers changes. In a statement to Ars Technica, Meta said it had opened a bug bounty programme for Muse and welcomed reports from researchers. The company paused the feature after Claroc reported the problem through the programme and attempted to contact Meta directly. As of now, Muse users cannot create new share links, reducing the risk of further exposure.
What you should do
If you have shared conversations using Muse, assume that the content may have been accessible to others. Review any shared links and consider what information was included. For businesses, check if staff used Muse to discuss confidential topics and take steps to limit further exposure. Wait for Meta's updates on changes to the sharing feature before using it again.
Why it matters
This incident shows how a small design decision can lead to serious privacy risks, even for products marketed as secure. It highlights the importance of reviewing how sharing features are implemented, especially in tools that handle sensitive information.
Key points
- Meta Muse's share links exposed private conversations due to a design flaw.
- Researchers found over 6,800 accessible links with sensitive information.
- Meta has suspended the sharing feature while it reviews the issue.
- The flaw was in how conversation titles were included in the share link's web address.
- Users who shared sensitive information via Muse should review what may have been exposed.
Sources
Ars Technica
Reference
Wired
Reference
