SB2021072073 - Ubuntu update for linux

Description

This security bulletin contains information about 5 secuirty vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2021-23134)

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

The vulnerability exists due to a use-after-free error in nfc sockets in the Linux Kernel. A local user with the CAP_NET_RAW capability can trigger use-after-free and escalate privileges on the system.

2) Race condition (CVE-ID: CVE-2021-32399)

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

The vulnerability exists due to a race condition  for removal of the HCI controller within net/bluetooth/hci_request.c in the Linux kernel. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

3) Use-after-free (CVE-ID: CVE-2021-33034)

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

The vulnerability exists due to a use-after-free error in net/bluetooth/hci_event.c when destroying an hci_chan. A local user can escalate privileges on the system.

4) Integer overflow (CVE-ID: CVE-2021-33909)

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

The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.

Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.

5) Out-of-bounds read (CVE-ID: CVE-2021-3506)

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition in fs/f2fs/node.c in the f2fs module in the Linux kernel. A local user can trigger out-of-bounds read error and read internal kernel information or crash the system.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/USN-5016-1