SB20261103103 - Ubuntu update for linux, linux-aws, linux-fips and more
Published: November 3, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Improper Resource Shutdown or Release (CVE-ID: CVE-2021-28714)
CWE-ID: CWE-404 - Improper Resource Shutdown or Release
CVSSv4: 7.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a remote user to perform a denial of service (DoS) attack.
The vulnerability exists due to incoming data packets for a guest in the Linux kernel's netback driver are buffered until the guest is ready to process them. A remote user can use a UDP connection on a fast interface to trigger resource exhaustion and perform a denial of service (DoS) attack.
2) Use-after-free (CVE-ID: CVE-2021-3640)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in sco_sock_sendmsg() function of the Linux kernel HCI subsystem. A privileged local user can call ioct UFFDIO_REGISTER or other way trigger race condition to escalate privileges on the system.
Remediation
Install update from vendor's website.