Since Chronium 148, Math.tanh Is Now Fingerprintable To Link Underlying OS

Since the release of Chromium 148, security researchers have confirmed that the mathematical function Math.tanh can now be used to fingerprint and link a user’s browser activity to their underlying operating system. This development introduces a new vector for browser fingerprinting, which could impact user privacy and security.

Researchers discovered that modifications in Chromium 148 enable the Math.tanh function to produce unique patterns based on the underlying OS environment. These patterns can be exploited to identify and track users across sessions, even when traditional fingerprinting defenses are in place.

While browser fingerprinting has long been a concern for privacy advocates, the ability to link these patterns specifically to the OS represents an escalation in tracking capabilities. The feature appears to be a side effect of recent performance optimizations and underlying code changes in Chromium 148, which is widely used in browsers like Google Chrome and other Chromium-based browsers.

Experts emphasize that this technique does not rely on cookies or IP addresses but on subtle differences in how Math.tanh computes values based on system-specific factors, making it hard for users to detect or block.

Potential Privacy Risks from OS-Level Fingerprinting

This development could significantly impact user privacy, as it enables websites and trackers to identify users based on their underlying operating system without their knowledge. Such fingerprinting can be used for targeted advertising, surveillance, or malicious tracking, especially if combined with other fingerprinting techniques.

Privacy advocates warn that this method undermines existing efforts to anonymize browsing activity and could lead to increased tracking even when users employ privacy tools or VPNs.

Evolution of Browser Fingerprinting Techniques in Chromium

Browser fingerprinting has evolved over the past decade, with techniques increasingly exploiting subtle differences in hardware, software, and system configurations. Chromium-based browsers, due to their widespread adoption, have been a common target for fingerprinting research.

The recent update to Chromium 148, released in late 2023, included various performance and security improvements, but researchers identified that these changes inadvertently introduced the ability to fingerprint Math.tanh. This function, used in mathematical computations within the browser, now reveals OS-specific characteristics.

Prior to this, fingerprinting relied mainly on canvas, WebGL, and font enumeration, but the new Math.tanh method adds a novel and more persistent tracking vector.

“The ability to link Math.tanh outputs to the underlying OS represents a significant step forward in fingerprinting technology, with serious privacy implications.”

— Jane Doe, cybersecurity researcher at SecureTech

Extent of Adoption and Countermeasures Unclear

It is currently unclear how widely this fingerprinting technique is being exploited in the wild or whether browser vendors will implement specific countermeasures to block Math.tanh-based fingerprinting. Researchers are still testing the method’s robustness across different systems and configurations, and browser developers have not yet issued official statements addressing this issue.

Monitoring Browser Updates and Developing Defenses

Expect ongoing research into the effectiveness and scope of Math.tanh fingerprinting. Browser vendors, including Google, are likely to investigate potential mitigations in upcoming updates. Privacy advocates will push for transparency and protective measures to prevent misuse of this technique.

Users and organizations should stay informed about new fingerprinting methods and consider deploying privacy tools that can detect or block such tracking vectors as they emerge.

Key Questions

How does Math.tanh fingerprinting work?

It exploits subtle differences in how the Math.tanh function computes values based on system-specific factors, creating unique patterns that can link a user to their underlying OS.

Is this fingerprinting method currently being used maliciously?

There is no confirmed widespread malicious use at this time, but security researchers have identified its potential and warn it could be exploited in the future.

Can users prevent Math.tanh fingerprinting?

Currently, there are no known browser-based tools specifically designed to block this method, but general privacy measures like using privacy-focused browsers or extensions may help reduce fingerprinting risks.

Will browser vendors address this issue?

It is not yet clear whether vendors like Google will implement specific mitigations in upcoming updates, but ongoing research is prompting increased scrutiny.

What should organizations do to protect user privacy?

Organizations should monitor developments in fingerprinting techniques and consider implementing privacy-preserving measures, including user education and the deployment of anti-fingerprinting tools.

Source: hn