junian.dev

PSA for macOS users: 1. Apple’s supplied SSL certificate bundle at /etc/ssl/cert.pem still trusts certificates attackers can forge using compromised eMudhra keys. 2. I confirmed this on macOS 26.7.1 and 27.0.1 using Apple’s built-in curl and Git. 3. An attacker intercepting connections from tools using this bundle could replace downloads with malware. With commands like curl … | sh, that malware would execute immediately. 4. Removing the roots that authorize those certificates blocks the tested chains. Both OS updates restored roots I’d previously removed, requiring me to remove them again. 4. I’ve submitted the findings to Apple’s security team and am awaiting their response. In the meantime, you can apply a temporary fix as outlined below. 5. To check and fix your machine, give an agent like ChatGPT/Codex or Claude Code the following prompt: “Independently verify whether Apple’s /etc/ssl/cert.pem still permits trust in certificates signed with compromised eMudhra keys. If so, back it up and remove the roots enabling that trust, identified by verified SPKI fingerprints. Confirm Apple’s built-in curl and Git reject those chains while ordinary HTTPS still works. Preserve rollback and never disable TLS verification.” Note that removing these roots can also block legitimate sites. This is a temporary mitigation, not a substitute for a fix from Apple. I’ll share the script I used in a follow-up post if you’d prefer to use that directly.