How to Optimize Performance in Complex Race Conditions

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.

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

[00:00:00] Introduction

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

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

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

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

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

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

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

The DAY[0] Podcast episodes are streamed live on Twitch twice a week:

-- Mondays at 3:00pm Eastern (Boston) we focus on web and more bug bounty style vulnerabilities

-- Tuesdays at 7:00pm Eastern (Boston) we focus on lower-level vulnerabilities and exploits.

We are also available on the usual podcast platforms:

-- Apple Podcasts: https://podcasts.apple.com/us/podcast/id1484046063

-- Spotify: https://open.spotify.com/show/4NKCxk8aPEuEFuHsEQ9Tdt

-- Google Podcasts: https://www.google.com/podcasts?feed=aHR0cHM6Ly9hbmNob3IuZm0vcy9hMTIxYTI0L3BvZGNhc3QvcnNz

-- Other audio platforms can be found at https://anchor.fm/dayzerosec

You can also join our discord: https://discord.gg/daTxTK9