Senior LevelWeb Security & Cyber Defense
How do Spectre and Meltdown speculative execution CPU vulnerabilities impact web browsers and SharedArrayBuffer?
❓ Interview Prompt: Explain Spectre / Meltdown, CPU speculative execution side-channels, timing attacks on process memory, and browser isolation requirements (COOP/COEP).
Spectre and Meltdown exploit hardware speculative execution features in modern CPUs to read arbitrary memory across process boundaries:
Impact on Web Browsers:
In JavaScript, attackers used high-resolution timers ('performance.now()') and 'SharedArrayBuffer' to execute cache-timing attacks reading memory across sites co-located in the same renderer process!
Browser Mitigations (Cross-Origin Isolation):
Browsers restricted 'SharedArrayBuffer' unless pages explicitly enable Cross-Origin Isolation via two headers:
1
'Cross-Origin-Opener-Policy: same-origin' (COOP).
2
'Cross-Origin-Embedder-Policy: require-corp' (COEP).
Code Implementation Example
http
HTTP/1.1 200 OK
Cross-Origin-Opener-Policy: same-origin
Cross-Origin-Embedder-Policy: require-corp💡Cross-Origin Isolation HTTP headers enabling SharedArrayBuffer safely.
🎯 Interview Key Takeaway
Enable COOP and COEP HTTP headers to establish Cross-Origin Isolation and mitigate Spectre CPU memory side-channel vulnerabilities.
#Spectre#Meltdown#COOP/COEP#Hardware Security#Senior
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