This affects the package celery before 5.2.2. It by default trusts the messages and metadata stored in backends (result stores). When reading task metadata from the backend, the data is deserialized. Given that an attacker can gain access to, or somehow manipulate the metadata within a celery backend, they could trigger a stored command injection vulnerability and potentially gain further access to the system.
github.com/celery/celery
github.com/celery/celery/blob/master/Changelog.rst%23522
github.com/celery/celery/commit/1f7ad7e6df1e02039b6ab9eec617d283598cad6b
lists.fedoraproject.org/archives/list/[email protected]/message/SYXRGHWHD2WWMHBWCVD5ULVINPKNY3P5
nvd.nist.gov/vuln/detail/CVE-2021-23727
snyk.io/vuln/SNYK-PYTHON-CELERY-2314953