Pool-Party: Exploiting Browser Resource Pools for Web Tracking

Peter Snyder, Soroush Karami, Arthur Edelstein, Benjamin Livshits, Hamed Haddadi | Privacy

We identify class of covert channels in browsers that are not mitigated by current defenses, which we call “pool-party” attacks. Pool-party attacks allow sites to create covert channels by manipulating limited-but-unpartitioned resource pools. These class of attacks have been known, but in this work we show that they are both more prevalent, more practical for exploitation, and allow exploitation in more ways, than previously identified. These covert channels have sufficient bandwidth to pass cookies and identifiers across site boundaries under practical and real-world conditions. We identify pool-party attacks in all popular browsers, and show they are practical cross-site tracking techniques (i.e., attacks take 0.6s in Chrome and Edge, and 7s in Firefox and Tor Browser).

In this paper we make the following contributions: first, we describe pool-party covert channel attacks that exploit limits in application-layer resource pools in browsers. Second, we demonstrate that pool-party attacks are practical, and can be used to track users in all popular browsers; we also share open source implementations of the attack and evaluate them through a representative web crawl. Third, we show that in Gecko based-browsers (including the Tor Browser) pool-party attacks can also be used for cross-profile tracking (e.g., linking user behavior across normal and private browsing sessions). Finally, we discuss possible mitigation strategies and defenses.

View paper


Ready for a better Internet?

Brave’s easy-to-use browser blocks ads by default, making the Web cleaner, faster, and safer for people all over the world.


Almost there…

You’re just 60 seconds away from the best privacy online

If your download didn’t start automatically, .

  1. Download Brave

    Click “Save” in the window that pops up, and wait for the download to complete.

    Wait for the download to complete (you may need to click “Save” in a window that pops up).

  2. Run the installer

    Click the downloaded file at the top right of your screen, and follow the instructions to install Brave.

    Click the downloaded file, and follow the instructions to install Brave.

  3. Import settings

    During setup, import bookmarks, extensions, & passwords from your old browser.

Need help?

Get better privacy. Everywhere!

Download Brave mobile for privacy on the go.

Download QR code
Click this file to install Brave Brave logo
Click this file to install Brave Brave logo
Click this file to install Brave Brave logo