GPUs From All Major Suppliers Are Vulnerable To New Pixel-Stealing Attack

An anonymous reader quotes a report from Ars Technica: GPUs from all six of the major suppliers are vulnerable to a newly discovered attack that allows malicious websites to read the usernames, passwords, and other sensitive visual data displayed by other websites, researchers have demonstrated in a paper (PDF) published Tuesday. The cross-origin attack allows a malicious website from one domain -- say, example.com -- to effectively read the pixels displayed by a website from example.org, or another different domain. Attackers can then reconstruct them in a way that allows them to view the words or images displayed by the latter site. This leakage violates a critical security principle that forms one of the most fundamental security boundaries safeguarding the Internet. Known as the same origin policy, it mandates that content hosted on one website domain be isolated from all other website domains. [...] GPU.zip works only when the malicious attacker website is loaded into Chrome or Edge. The reason: For the attack to work, the browser must: 1. allow cross-origin iframes to be loaded with cookies2. allow rendering SVG filters on iframes and3. delegate rendering tasks to the GPU For now, GPU.zip is more of a curiosity than a real threat, but that assumes that Web developers properly restrict sensitive pages from being embedded by cross-origin websites. End users who want to check if a page has such restrictions in place should look for the X-Frame-Options or Content-Security-Policy headers in the source. "This is impactful research on how hardware works," a Google representative said in a statement. "Widely adopted headers can prevent sites from being embedded, which prevents this attack, and sites using the default SameSite=Lax cookie behavior receive significant mitigation against personalized data being leaked. These protections, along with the difficulty and time required to exploit this behavior, significantly mitigate the threat to everyday users. We are in communication and are actively engaging with the reporting researchers. We are always looking to further improve protections for Chrome users." An Intel representative, meanwhile, said that the chipmaker has "assessed the researcher findings that were provided and determined the root cause is not in our GPUs but in third-party software." A Qualcomm representative said "the issue isn't in our threat model as it more directly affects the browser and can be resolved by the browser application if warranted, so no changes are currently planned." Apple, Nvidia, AMD, and ARM didn't comment on the findings. An informational write-up of the findings can be found here.

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