Lab: Single-endpoint race conditions
Summary: PortSwigger's lab demonstrates a single-endpoint race condition in an email change feature, where the site stores only one pending email address at a time and overwrites it rather than appending. Sending parallel POST /my-account/change-email requests causes confirmation emails to go to the wrong address, letting a user claim carlos@ginandjuice.shop and inherit its pending administrator invite.
What you should know: The flaw turns a routine profile update into privilege escalation: an address with a pending admin invite is claimable by anyone who wins the race window between the database write and the confirmation email. A single pending-value field with no locking is all it takes.
Read the original at PortSwigger Research ↗
- Topics
- Vulnerabilities & Patching
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