Collected research

Hacking AWS Cognito Misconfigurations

Sunil Yadav · NotSoSecure · 17 February 2020

A login-only application exposed its AWS Cognito app client and pool identifiers in the client-side JavaScript SDK, and Cognito still permitted self sign-up. The new account's token minted temporary AWS credentials with full Lambda rights, so rewriting a Lambda function to print its environment variables leaked privileged keys and led to account takeover.

Record

Researcher

Sunil Yadav

Published by

NotSoSecure

Date

17 February 2020

Topic

Other

In the archive

• Collected in the 2020 research round

Tags

• privilege-escalation
• auth-bypass
• info-leak
• aws
• jwt
• javascript
• attack-chain
• case-study
• owasp-a01-2021
• owasp-a07-2021

This page is the archive's own catalogue record. The research is the work of Sunil Yadav, first published at the original source. Preserved copies are kept so the citation survives its host; this one was last captured on 11 August 2026.