Race Condition Hackviser

| Mitigation | Bypass via Hackviser | |------------|----------------------| | | Use /proc/self/fd symlink attack to bypass lock scope | | Atomic operations (CAS) | Race after CAS but before commit (e.g., double-fetch) | | Transaction isolation (SERIALIZABLE) | Use read-only race + out-of-band channel (cache side-channel) | | Deterministic scheduling (TSO) | Introduce async signals or page faults to deschedule victim |

When a user uploads a file, some applications temporarily save it to a public directory before validating its extension and deleting it if it is malicious. An attacker can exploit this window by uploading a web shell (like a .php file) and immediately requesting that file via a concurrent script before the application has time to delete it. How to Test for Race Conditions race condition hackviser

: The application verifies if the user has permission or sufficient resources (e.g., "Does this user have enough balance to withdraw $100?"). race condition hackviser