Application programming interfaces (APIs) are a critical part of the modern web. They allow developers to build powerful applications that can interact with websites and other online services. However, APIs can also be misused by attackers to scrape private user information from websites.
How APIs are Being Misused to Scrape Private User Information from Websites
There are a number of ways that attackers can misuse APIs to scrape private user information. One common method is to use a technique called “web scraping.” Web scraping involves using automated tools to extract data from websites. Attackers can use web scraping to scrape large amounts of data from websites, including private user information such as names, email addresses, and passwords. It is important to obtain permission from the website owner before scraping their data, and to only scrape data that is publicly available.
Another way that attackers can misuse APIs to scrape private user information is to exploit vulnerabilities in the APIs themselves. API vulnerabilities can have a serious impact on organizations. They can be used to steal sensitive data, launch denial-of-service attacks, or even take control of systems. It is important for organizations to take steps to secure their APIs and prevent API vulnerabilities from being exploited. For example, in 2021, a vulnerability in the Microsoft Exchange Server API was exploited by attackers to steal the email data of millions of users.
How to Stay Protected
API misuse is a serious threat to user privacy. Organizations that use APIs need to take steps to secure their APIs and prevent them from being misused by attackers. Here are a few best practices for securing APIs:
- Use strong authentication and authorization mechanisms to control access to APIs.
- Implement API security testing to identify and fix vulnerabilities.
- Monitor APIs for suspicious activity.
- Educate developers about API security best practices.
By following these best practices, organizations can help to protect their users from the threat of API misuse.
Our Team works alongside clients and guides them through the NCSC Cyber Essentials certification process. This is a self-assessment process in which clients will be given access to an online platform to answer key questions about their infrastructure; and guarantee their certification.
Examples of Recent Data Breaches Related to APIs
- In early 2023, a hacker scraped over 200 million records from X (formally known as Twitter) and posted them on a popular hacking forum. The data was obtained in 2021 by exploiting an API that allowed email addresses to be resolved to user profiles. The data included email addresses, names, usernames, and follower counts.
- 2.6 million records of data scraped from Duolingo were leaked on a popular hacking forum in August 2023. The data was obtained by exploiting a vulnerability in Duolingo’s API and had been for sale since January 2023. The data included email addresses, names, the languages being learned, XP (experience points), and other data related to learning progress on Duolingo. While some of the data attributes are intentionally public, the ability to map private email addresses to them presents an ongoing risk to user privacy.
- In January 2014, just one week after Gibson Security detailed vulnerabilities in Snapchat’s systems, a hacker exploited a vulnerability in Snapchat’s API to gain access to the usernames and phone numbers of 4.6 million users. The hacker used a brute force attack to enumerate a large number of phone numbers against the API. This attack was possible because Snapchat had previously asserted that such an attack was “theoretical.” The breach allowed the hacker to resolve individual usernames (which are often used across other services) to phone numbers, which users typically wish to keep private.
These are just a few examples of the many data breaches that have been caused by API misuse. It is clear that API misuse is a serious threat to user privacy. Organizations that use APIs need to take steps to secure their APIs and prevent them from being misused by attackers.