Researchers Uncover New GPU Side-Channel Vulnerability Leaking Sensitive Data

Researchers Uncover New GPU Side-Channel Vulnerability Leaking Sensitive Data

A novel side-channel attack called renders virtually all modern graphics processing units (GPU) vulnerable to information leakage.

Graphical data compression is a feature in integrated GPUs (iGPUs) that allows for saving memory bandwidth and improving performance when rendering frames, compressing visual data losslessly even when it’s not requested by software.

The study found that the compression, which happens in various vendor-specific and undocumented ways, induces data-dependent DRAM traffic and cache occupancy that can be measured using a side-channel.

Successful exploitation could allow a malicious web page to infer the values of individual pixels from another web page embedded in an iframe element in the latest version of Google Chrome, effectively circumventing critical security boundaries such as same-origin policy (SOP).

Chrome and Microsoft Edge are particularly vulnerable to the attack because they allow cross-origin iframes to be loaded with cookies, permit rendering SVG filters on iframes, and delegate rendering tasks to the GPU. However, Mozilla Firefox and Apple Safari are not impacted.

This, in turn, is rooted in the fact that some web standards allow for the framing page to apply visual effects (i.e., SVG filters) to the iframed page, thereby exposing the mechanism to side-channel attacks by, say, computing the time differences between rendering black and white pixels and then distinguish between them using the timing information.

Affected GPUs include those from AMD, Apple, Arm, Intel, Nvidia, and Qualcomm. That said, websites that already deny being embedded by cross-origin websites via X-Frame-Options and Content Security Policy (CSP) rules are not susceptible to the pixel-stealing attack.