Simon Koeck
Security researcher and developer. I find vulnerabilities
and write about them.
Most popular writeups
critical / Google DevSite
How I Found a $90,000 Remote Code Execution Vulnerability in Google
A Flask cookie on developers.google.com was signed with a secret it carried inside itself. Pulling that secret out turned a forged session into code execution across Google's developer sites.
high / React
A Single POST Freezes Any Next.js Server
To rebuild one submitted form, React scanned every field in the request once for each reference it contained. Nothing capped either number, so one 900 KB POST makes the server do 100 million checks and freeze.
critical / n8n
From a Schema Name to RCE in n8n
n8n used a user-supplied schema name as a key on a plain object. Setting it to __proto__ polluted the prototype and led to RCE through the Git node.