Eight eMudhra intermediates had private keys weak enough to recover almost instantly
Mozilla and Google said eight eMudhra intermediate certificate keys were generated with insufficient randomness, allowing their recovery and potentially the creation of fraudulent certificates for any domain. Browsers moved to block them; Mozilla completed its Firefox blocklist rollout in under three hours, while other software may still need updates. eMudhra says none of the intermediates issued end-entity certificates, and sources report no confirmed exploitation.
Bottom line — The immediate risk now lies in clients that still trust the eight intermediates and do not receive revocation updates.
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Mozilla says the eight P-384 private keys were integers below 256 and could be recovered near instantly.
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Google says Chrome blocked the affected TLS keys on 17 October; Apple and Microsoft protections followed on 19 and 20 October, according to the incident site.
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Mozilla says six affected intermediates were for TLS and two for code signing; the cross-signed certificates used the same keys.
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eMudhra’s preliminary account blames a flaw in a key-generation script that created a second, weaker set of keys, which were used by mistake.
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eMudhra says only one affected intermediate was deployed in production and none issued end-entity certificates.
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Google says no certificates chaining to the six affected TLS intermediates appeared in Certificate Transparency logs before Chrome’s block.
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Cloudflare says its review found no active exploitation on its services and that it has updated shared trust stores and affected products.
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Mozilla says the NSS 3.131.1 update removes the signing root to help protect applications that do not receive Firefox’s OneCRL updates.