CVE-2021-0920

Leveraging Time-of-Check and Time-of-Use (TOCTOU) Race Conditions (CAPEC-29)

This attack targets a race condition occurring between the time of check (state) for a resource and the time of use of a resource. A typical example is file access. The adversary can leverage a file access race condition by "running the race", meaning that they would modify the resource between the first time the target program accesses the file and the time the target program uses the file. During that period of time, the adversary could replace or modify the file, causing the application to behave unexpectedly.

Leveraging Race Conditions (CAPEC-26)

The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.

CVE.org

View more information about CVE-2021-0920 on the official MITRE CVE website.

NIST National Vulnerability Database

CVE-2021-0920 on the NIST NVD.

CISA Known Exploited Vulnerabilities

CISA KEV