[binary] TOCTOUs in Intel SMM and Shannon Baseband Bugs

Published: March 23, 2023, midnight

We've got a pretty nice root/super-use check bypass in XNU this week, and a sort of double fetch issue in Intel's SMM leading to a potential privilege escalation into the Management system. We've also got a few meme-able Shannon Baseband issues and some tough to exploit out of bound reads in MIT Kerberos V5.

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Links and vulnerability summaries for this episode are available at: https://dayzerosec.com/podcast/198.html

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[00:00:00] Introduction

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[00:00:27] Spot the Vuln - The Right Context

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[00:02:52] Discussion: Using GPT-4 to Spot Vulnerabilities in Code (and SecGPT)

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[00:11:05] A Race to Report a TOCTOU: Analysis of a Bug Collision in Intel SMM

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[00:19:32] Out-of-Bounds Read in the MIT Kerberos V5 (krb5) library

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[00:25:35] XNU: NFSSVC root check bypass; use after free due to insufficient locking in upcall worker threads

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[00:32:36] XNU: NFSSVC root check bypass; use after free due to insufficient locking in upcall worker threads

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[00:36:35] Shannon Baseband: Intra-object overflow in NrmmMsgCodec when decoding Service Area List

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