Details for this vulnerability have not been published by NIST at this point. Descriptions from software vendor advisories for this issue are provided below.
It was discovered that BlueZ incorrectly handled the Discoverable status when a device is powered down. This could result in devices being powered up discoverable, contrary to expectations. This issue only affected Ubuntu 20.04 LTS, Ubuntu 21.04, and Ubuntu 21.10. (CVE-2021-3658)
It was discovered that BlueZ incorrectly handled certain memory operations. A remote attacker could possibly use this issue to cause BlueZ to consume resources, leading to a denial of service. (CVE-2021-41229)
It was discovered that the BlueZ gatt server incorrectly handled disconnects. A remote attacker could possibly use this issue to cause BlueZ to crash, leading to a denial of service. (CVE-2021-43400)