Published on March 22nd, 2021 📆 | 4713 Views ⚑0
Ubuntu Security Notice USN-4884-1 ≈ Packet Storm
Ubuntu Security Notice USN-4884-1
March 20, 2021
A security issue affects these releases of Ubuntu and its derivatives:
– Ubuntu 20.04 LTS
Several security issues were fixed in the Linux kernel.
– linux-oem-5.10: Linux kernel for OEM systems
Loris Reiff discovered that the BPF implementation in the Linux kernel did
not properly validate attributes in the getsockopt BPF hook. A local
attacker could possibly use this to cause a denial of service (system
It was discovered that the priority inheritance futex implementation in the
Linux kernel contained a race condition, leading to a use-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly execute arbitrary code. (CVE-2021-3347)
It was discovered that the network block device (nbd) driver in the Linux
kernel contained a use-after-free vulnerability during device setup. A
local attacker with access to the nbd device could use this to cause a
denial of service (system crash) or possibly execute arbitrary code.
The problem can be corrected by updating your system to the following
Ubuntu 20.04 LTS:
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
CVE-2021-20194, CVE-2021-3347, CVE-2021-3348