Wiz Research has identified a publicly accessible ClickHouse database belonging to DeepSeek, which allows full control over database operations, including the ability to access internal data. The exposure includes over a million lines of log streams containing chat history, secret keys, backend details, and other highly sensitive information. The Wiz Research team immediately and responsibly disclosed the issue to DeepSeek, which promptly secured the exposure.
In this blog post, we will detail our discovery and also consider the broader implications for the industry at large. As DeepSeek made waves in the AI space, the Wiz Research team set out to assess its external security posture and identify any potential vulnerabilities.
Within minutes, we found a publicly accessible ClickHouse database linked to DeepSeek, completely open and unauthenticated, exposing sensitive data. It was hosted at oauth2callback. This database contained a significant volume of chat history, backend data and sensitive information, including log streams, API Secrets, and operational details.
More critically, the exposure allowed for full database control and potential privilege escalation within the DeepSeek environment, without any authentication or defense mechanism to the outside world. By mapping the external attack surface with straightforward reconnaissance techniques passive and active discovery of subdomains , we identified around 30 internet-facing subdomains. Most appeared benign, hosting elements like the chatbot interface, status page, and API documentation—none of which initially suggested a high-risk exposure.
Upon further investigation, these ports led to a publicly exposed ClickHouse database , accessible without any authentication at all — immediately raising red flags. ClickHouse is an open-source, columnar database management system designed for fast analytical queries on large datasets. It was developed by Yandex and is widely used for real-time data processing, log storage, and big data analytics, which indicates such exposure as a very valuable and sensitive discovery.
