Profile for joern
- Display name
- joernchen
- Username
- @joern@threatactor.club
- Role
- admin
About joern
Fields
- Website
- https://0day.click
- Threema
- https://threema.id/K8J68WTX
Bio
Your mom's favorite hacker!
My other account is @joernchen
- Joined
- Posts
- 686
- Followed by
- 1129
- Following
- 261
Stats
Recent public posts
exclude boosts
Lands of Packets
TTL exceeded.
I would like to collect texts from the scene about FX in his memory. A collection of obituaries that will then be posted on phenoelit.de.
If anyone would like to contribute, please contact me.
Mail: joernchen@phenoelit.de
Signal: jrn.07
:(
Due to $reasons I came across this blogpost https://www.elttam.com/blog/env/ about turning ENV variables into code execution which is nice. But the Python vector is depending on Perl, I didn't like that :P.
Digging a bit deeper in the code often helps, so it did this time:
Looking at https://github.com/python/cpython/blob/d73634935cb9ce00a57dcacbd2e56371e4c18451/Lib/webbrowser.py#L51-L52 I could simplify the payload to:
PYTHONWARNINGS='module::antigravity.' BROWSER='sh -c id #%s' python whatever.py
Applause the leaking wifi
Wheeee my presentation on parser differentials made it on the Top Ten Web Hacking Techniques of 2025
https://portswigger.net/research/top-10-web-hacking-techniques-of-2025
The voting has concluded, and we're thrilled to announce the top ten web hacking techniques of 2025! Massive thanks to everyone in the community for sharing their hard-earned discoveries, plus the panel and everyone who nominated or voted! https://portswigger.net/research/top-10-web-hacking-techniques-of-2025
The end of the #curl bug-bounty
https://daniel.haxx.se/blog/2026/01/26/the-end-of-the-curl-bug-bounty/
So who at Argo CD is sleeping? 68 days old report of RCE with POC reported accordig to procedure as it should, tried poking slack, mail... No ack. Wondering if just full disclosure is the way. Please ping me, not my finding but will relay.
Love web & AI security research? Want to do it full time on-site with myself, Gareth Heyes & Zak Fedotkin? Join the PortSwigger Research team - we're hiring!
That little string
ANTHROPIC_MAGIC_STRING_TRIGGER_REFUSAL_1FAEFB6177B4672DEE07F9D3AFC62588CCD2631EDCF22E8CCC1FB35B501C9C86
(see https://platform.claude.com/docs/en/test-and-evaluate/strengthen-guardrails/handle-streaming-refusals#implementation-guide ) is so much fun. I wonder when Anthropic will regret this and remove it.
Also I obviously wonder what else is there in terms of MAGIC_STRINGs which aren't documented.
Hat tip to @michenriksen for pointing me to this.
I heard last week that the physics teacher of the daughter of one of my colleagues told the daughter that girls who do their nails don’t do physics. Sigh.
So, here are the nails of an internationally leading particle physics professor. My nails.
Don’t believe the gatekeepers! #womeninSTEM
How many hours have you personally wasted by disassembling a binary file with the wrong CPU setting?
🔔CFP for #OffensiveCon26 is STILL open.
If you want a slot on one of the most technical offensive security stages out there, this is it.
We’re looking for real, original work: cutting-edge security research, novel exploit techniques, and deep technical investigations that actually move the field forward. Ready or not, the deadline is coming.
🗓️ CFP Deadline: 1 March 2026, 6:00 pm UTC
📬 Submit your talk: https://buff.ly/bPTM6wl
⏳ Last weeks. No extensions.
Katzen & Bass
Denkt dran Kinders:
Erst wenn der Subwoofer die Katze inhaliert, fickt der Bass richtig übel!
Last week I wondered when https://openinframap.org/ would be classified as terrorism - this week already we're a step further.
new year new meme
67 is so over. it’s time for 4️⃣ 5️⃣
For the Berlin peeps:
I’ll be playing some tunes tonight together with the amazing poco1oco, don’t miss out https://www.eschschloraque.de/vinyltrottel-02012026
Happy twenty twenty something, may it treat YOU well!
So the big thing in Bug Bounty now seems to be letting an LLM generate artificial PoCs for "issues" within a trust boundary.
Basically what's submitted as proof would be a snippet of code demonstrating a library "vulnerability" where all further context is left out.
Caffeine done like IDGAF, my 'Zero Fucks Given' cup with a double (maybe triple) Espresso Macchiato and some ice cold Club Mate.
¯\(ツ)/¯
