SB2021082431 - Ubuntu update for linux

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Double Free (CVE-ID: CVE-2021-3564)

The vulnerability allows a local attacker to perform a denial of service attack.

The vulnerability exists due to bluetooth subsystem in the Linux kernel does not properly handle HCI device detach events. An attacker with physical access to the system can trigger double free error and perform a denial of service attack.

2) Use-after-free (CVE-ID: CVE-2021-3573)

The vulnerability allows local user to escalate their privileges on the system.

The vulnerability exists due to a use-after-free in hci_sock_bound_ioctl() function of the Linux kernel HCI subsystem triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user can use this flaw to crash the system or escalate privileges on the system.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-5044-1