In case you're wondering how this could be worse than Heartbleed:
Yes, apparently the allocation patterns inside Cloudflare mean TLS keys aren't exposed to this vulnerability.
But Heartbleed happened at the TLS layer. To get secrets from Heartbleed, you had to make a particular TLS request that nobody normally makes.
Cloudbleed is a bug in Cloudflare's HTML parser, and the secrets it discloses are mixed in with, apparently, HTTP response data. The modern web is designed to cache HTTP responses aggressively, so whatever secrets Cloudflare revealed could be saved in random caches indefinitely.
You really want to see Cloudflare spend more time discussing how they've quantified the leak here.
Yes, apparently the allocation patterns inside Cloudflare mean TLS keys aren't exposed to this vulnerability.
But Heartbleed happened at the TLS layer. To get secrets from Heartbleed, you had to make a particular TLS request that nobody normally makes.
Cloudbleed is a bug in Cloudflare's HTML parser, and the secrets it discloses are mixed in with, apparently, HTTP response data. The modern web is designed to cache HTTP responses aggressively, so whatever secrets Cloudflare revealed could be saved in random caches indefinitely.
You really want to see Cloudflare spend more time discussing how they've quantified the leak here.