The online real estate platform Redfin has addressed a technical error on its website that briefly exposed the personal contact information of some users. The vulnerability, which was active for less than a week, made names, email addresses, and phone numbers visible on property listing pages.
A company spokesperson confirmed the issue was resolved as soon as it was identified. The flaw involved contact forms on rental listings, which would sometimes pre-populate with the data of a previous visitor, making it visible to the next user viewing the page.
Key Takeaways
- A technical flaw on Redfin's website exposed some users' personal contact information, including names, emails, and phone numbers.
- The data was visible on contact forms for property listings and was active for less than one week.
- The vulnerability affected both desktop and mobile versions of the site before being fixed.
- Redfin stated the error was remediated as soon as the company became aware of it.
Details of the Data Exposure
The security issue stemmed from the way contact forms on Redfin's property listings functioned. When a user visited a listing, a form designed to contact a real estate agent would appear. For a brief period, this form would momentarily display the pre-filled personal details of a previous user.
While the information would quickly disappear for most users, it remained persistently visible for anyone viewing the website with JavaScript disabled. JavaScript is a common web technology used to create interactive elements on pages, and most modern browsers allow users to turn it off.
By disabling this feature, the contact forms would consistently display the email address or phone number, and sometimes both, of a past visitor. This allowed the information to be viewed without the brief time limit experienced by typical users. Investigations confirmed that the exposed data belonged to real individuals and was not placeholder or test information.
What is Pre-Filling?
Pre-filling is a common web feature where forms automatically populate with saved user information to make them easier and faster to complete. However, if not implemented correctly, it can lead to security vulnerabilities where one user's data is inadvertently shown to another.
Redfin's Response and Remediation
Redfin acknowledged the vulnerability after being contacted about the issue. The company framed the incident as a temporary technical problem affecting a small window of time.
“We recently identified a technical error on the website that temporarily made it possible for the e-mail address and/or phone number of a previous visitor to be visible to another user on a rental listing page,” said Alina Ptaszynski, a Redfin spokesperson. “This error was active for less than a week and was remediated as soon as we were made aware of it.”
The company initially rolled out a fix for the desktop version of its website. However, the vulnerability persisted on the mobile version of the site. After a subsequent inquiry, Redfin updated its mobile listings to close the security gap completely.
The company did not comment on whether it had found evidence of the vulnerability being exploited to collect user information in bulk. Because the flaw displayed one user's information at a time per page load, it could have been possible for a malicious actor to systematically visit numerous pages to gather a large volume of data.
Redfin's User Base
Redfin is a major player in the online real estate market, with its parent company, Rocket, reporting approximately 50 million monthly users on the platform. This large user base highlights the potential scale of even short-lived data exposures.
Implications for User Privacy
This incident raises questions about data handling and user privacy on large online platforms. While many companies share user data with third parties for legitimate business reasons, such as connecting a home buyer with an agent, it is typically done with explicit user consent and clear disclosures.
Redfin's privacy policy notes that it may share private information, but usually when the prompt to provide that data is accompanied by a specific disclosure. The contact form at the center of this vulnerability did not include a disclaimer warning users that their information might be displayed to subsequent visitors.
The inadvertent exposure of personal contact details like phone numbers and email addresses can expose individuals to risks such as:
- Phishing scams
- Unsolicited marketing calls or emails
- Identity theft attempts
While the duration of this specific flaw was short, it serves as a reminder of the constant need for rigorous security testing and transparent data privacy practices for any service that handles sensitive personal information.
