Xeno Kovah
@xenokovah.bsky.social
290 followers 27 following 220 posts
Interested in reverse engineering, firmware, bluetooth, trusted computing, and training. Founder of OpenSecurityTraining2 https://ost2.fyi
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xenokovah.bsky.social
WiFi security researchers: I want to get a TX amp to let my BT research tools connect back to further-away advertisers. I’m considering www.digikey.com/en/products/... . Is there a better option that’s used in the WiFi space that I could be considering?(Needs to work with USB BT dongles)
Reposted by Xeno Kovah
opensectraining.bsky.social
🙌We're happy to announce OST2 now has over 31k students registered! 🥳 By the time we noticed we crossed the 30k mark, we were already at 30.5, so we figured we'd wait for 31k, which is now!🎉

👏Kudos to all the students taking and finishing classes!👏
xenokovah.bsky.social
If elected to the role of Global Supreme Documentation Overlord Czar, I promise a chicken in every pot, and a README.md in every subfolder!
xenokovah.bsky.social
But I know some people would prefer to read rather than listen (and videos have poor random-access properties, even with subtitles). So I'll continue to think on it.
xenokovah.bsky.social
I’m not sure if I want to create a whitepaper for this or not. I feel like slides with animations are a much more effective and succinct way to get across what I’m trying to say, compared to e.g. taking a half-page to saying the same thing as 3-4 animated slides...
xenokovah.bsky.social
The good news is also the bad news: 2 days of slide-making and I’m over 100 slides…to describe the first 5 days of the work 😬 There’s no way I’m going to be able to include everything in the talk. I’ll post a “Kovah Cut” on the DarkMentor website like in the past, but may have to break into 2 talks
xenokovah.bsky.social
My new talk on reverse engineering the firmware of Realtek RTL8761B Bluetooth chips has been accepted to @hardwear-io.bsky.social in Amsterdam in November. Abstract in image due to size limits.
xenokovah.bsky.social
Mad props to the Realtek people for making their stuff Just Work in Linux in the first place, and of course the Linux contributors. (Of course...I'm not saying this completely-unverified firmware architecture is a good *security* architecture...but that's a point for a different time 😉)
xenokovah.bsky.social
I am quite simply gobsmacked that this worked on the first try! Nothing's ever this easy on Linux! 🤯
xenokovah.bsky.social
When I compress the output file and put it in to /lib/firmware/rtl_bt/rtl8761bu_fw.bin.zst on Ubuntu 24.04, all attached RTL8761B-based USB BT dongles Just Work with a patched BDADDR and clear presence of the custom LMP packet logging capability!
xenokovah.bsky.social
🧵It took me 1.25h to update my script (which does in-memory modification to the Realtek patches to insert my code before sending it to the chip) to output a copy of the modified Realtek patch file. …
xenokovah.bsky.social
My new talk on reverse engineering the firmware of Realtek RTL8761B Bluetooth chips has been accepted to @hardwear-io.bsky.social in Amsterdam in November. Abstract in image due to size limits.
xenokovah.bsky.social
Once I looked at the likely prerequisites, I updated the Bluetooth Learning Path to add in the BT/RE3113 class shown on the map here, which is the placeholder for talking in depth about my Realtek RE work in the future
opensectraining.bsky.social
With the release of ost2.fyi/BT2222, we have posted a brand new OST2 Bluetooth Learning Path which shows future classes that are planned, as well as classes which we need volunteers for. Freshly updated today: ost2.fyi/OST2_LP_Blue...
xenokovah.bsky.social
The ost2.fyi/BT2222 link has been updated to point at the new v2 URL and enrollment in the v1 class is no longer possible.
xenokovah.bsky.social
I changed it to be "A:B:[C]:F:[D:E]:G", so that students can collect their own local data from their own houses/work sooner, rather than exclusively looking at stuff pulled from the crowdsourcing server.
xenokovah.bsky.social
🧵I made a structural update to the Blue2thprinting #OST2 class today: The previous class was structured like "A:B:[C:D:E]:F:G" where F & G were collecting your own data, and [C-E] were understanding what Tell_Me_Everything.py was trying to tell you about the analyzed data…
xenokovah.bsky.social
The abuse of the term “ROM” continues unabated… I love how they even spell it out here and still don’t see the problem…
xenokovah.bsky.social
Random trivia: I hadn’t looked at the spec for this before, but apparently BT Classic masks the opposite side of the key relative to BT Low Energy when two parties negotiate a lower-strength encryption key ¯\_(ツ)_/¯
Reposted by Xeno Kovah
opensectraining.bsky.social
The "Trusted Computing 1102: Intermediate Trusted Platform Module (TPM) usage" ost2.fyi/TC2202 class release has updated 3 #OST2 learning paths

Secure Software Design & Implementation - ost2.fyi/OST2_LP_SecD...

System Security - ost2.fyi/OST2_LP_SysS...

Windows Security - ost2.fyi/OST2_LP_Wind...
xenokovah.bsky.social
FWIW it's vaguely possible I'll eventually turn my lessons learned here into a #OST2 5000-level RE class (after I get some more important and prerequisite classes like BT Classic done)
xenokovah.bsky.social
I'm still hoping they'll accept my workshop on Blue2thprinting as well, in which case I'll pull of a hat trick of talk, workshop, training!
xenokovah.bsky.social
My new talk on reverse engineering the firmware of Realtek RTL8761B Bluetooth chips has been accepted to @hardwear-io.bsky.social in Amsterdam in November. Abstract in image due to size limits.
xenokovah.bsky.social
The SEC-T organizers posted the video from my talk "Crowdsourcing Bluetooth identity, to understand Bluetooth vulnerability" in what seems like record time. You can find the video & slides (and previous truncated-for-time version) here: darkmentor.com/publication/...
Crowdsourcing Bluetooth identity, to understand Bluetooth vulnerability | Dark Mentor LLC
Bluetooth vulnerability assessment is still in the dark ages. We still don't have a good handle on all the devices that are affected by the exploitable-over-the-air vulnerabilities that we disclosed in Texas Instruments and Silicon Labs firmware back in 2020. But we've been chipping away at the problem!<p>We released "Blue2thprinting" in 2023 as our starting point towards something akin to nmap OS fingerprinting, but with a focus on learning what we could about the specific Bluetooth chip or firmware versions, to identify known-vulnerable versions. We delved into the thousands of pages of Bluetooth specs to extract bits and pieces, packets and profiles, that had interesting information to share about what a device is.<p>But even as we continue to add new types of data to enrich our understanding of what devices are, and whether they're vulnerable to known CVEs, there's just *so much* that's still unknown! In this talk we'll discuss the updates to Blue2thprinting to allow for P2P researcher data sharing and crowdsourcing, and how that can help broaden the global knowledge of Bluetooth vulnerability applicability. And we'll also highlight the ridiculous number of tantalizing known unknowns; and encourage you to join the BlueCrew on our Journey Into Mystery!
darkmentor.com
xenokovah.bsky.social
I’ve uploaded a good chunk of my Blue2thprinting data collected in Sweden at SEC-T to BTIDALPOOL.

And in honor of the Meshtastic workshops, I also added some Meshtastic UUIDs to CLUES which takes one from image 1 -> 2/3 (if you pass —verbose-print)