Luke Jahnke
nastystereo.com
Luke Jahnke
@nastystereo.com
400 followers 110 following 10 posts
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Reposted by Luke Jahnke
The Pentium's microcode ROM holds 414,720 bits in total: 4608 micro-instructions. For more photos of the Pentium's microcode circuitry along with a detailed explanation, see my latest blog post:
www.righto.com/2025/03/pent...
Notes on the Pentium's microcode circuitry
Most people think of machine instructions as the fundamental steps that a computer performs. However, many processors have another layer of ...
www.righto.com
Thank you! That motivates me to continue writing and sharing!
My latest blog post is live! Check your Ruby on Rails applications for the use of params[:_json]

nastystereo.com/security/rai...
Reposted by Luke Jahnke
Ten years ago, I realised I needed to rewrite ActiveScan++ in Java. After putting it off for so long that artificial intelligence was literally able to do 90% of the work for me, I've done it! It's now available in the BApp store. Report issues and feature requests here ->
github.com/albinowax/Ac...
GitHub - albinowax/ActiveScanPlusPlus: ActiveScan++ Burp Suite Plugin
ActiveScan++ Burp Suite Plugin. Contribute to albinowax/ActiveScanPlusPlus development by creating an account on GitHub.
github.com
Reposted by Luke Jahnke
Security researcher Luke Jahnke has published an escape for SafeMarshal, a new Ruby security gem that can be used to block deserialization attacks

nastystereo.com/security/rub...
Haha it is starting to feel like an advent calendar. But no, just a lot of free time lately. Maybe I need tougher targets, any suggestions?
My latest blog post is live 🔥 Read it to learn what SafeMarshal is and *two* very different ways to escape and get RCE!

Read it to find out why Date is *not* a safe class in Ruby or how to leverage serialized strings being constructed with string concatenation!

nastystereo.com/security/rub...
Reposted by Luke Jahnke
I've just rewritten ActiveScan++ in Java to lay the foundation for some major enhancements. It's not in the BApp store yet but if you'd like to take it for a spin you can grab it here:
github.com/albinowax/Ac...
GitHub - albinowax/ActiveScanPlusPlus: ActiveScan++ Burp Suite Plugin
ActiveScan++ Burp Suite Plugin. Contribute to albinowax/ActiveScanPlusPlus development by creating an account on GitHub.
github.com
I hope to write a follow up post that covers the footguns I learnt about for R apps, especially jsonlite::fromJSON ;)
New blog post is up!
Shiny Vulnerabilities in R's Most Popular Web Framework
nastystereo.com/security/r-s...

Turns out the programming language R is used for more than statistics, including web apps!
I think my post showing that Ruby's substring implementation is faulty is a little bit interesting, hoping someone else can chain it with another bug someday to show some true impact: nastystereo.com/security/rub...
Reposted by Luke Jahnke
Not sure how I missed that, but we now actually have Ken Thompson's C compiler backdoor code from the classic "Reflections on Trusting Trust". An excellent writeup by @swtch.com - research.swtch.com/nih.
research!rsc: Running the “Reflections on Trusting Trust” Compiler
research.swtch.com
My latest blog post is live! nastystereo.com/security/cro...

Read how to send a cross-site POST without including a Content-Type header (without CORS). It even works with navigator.sendBeacon
I just published a new blog post sharing an improved Deserialization Gadget Chain for Ruby!
It builds on the work of others, including Leonardo Giovanni, @ulldma.bsky.social and @vakzz.bsky.social

nastystereo.com/security/rub...