Skip to content
OpenAdvisories
High USN-4910-1 5 CVEs

linux, linux-aws, linux-azure, linux-gcp, linux-hwe-5.8, linux-kvm, linux-oracle, linux-raspi vulnerabilities

Published Apr 13, 2021 · Updated Jun 3, 2026

Summary

Ryota Shiga discovered that the sockopt BPF hooks in the Linux kernel could
allow a user space program to probe for valid kernel addresses. A local
attacker could use this to ease exploitation of another kernel
vulnerability. (CVE-2021-20239)

It was discovered that the BPF verifier in the Linux kernel did not
properly handle signed add32 and sub integer overflows. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. (CVE-2021-20268)

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.
(CVE-2021-3348)

吴异 discovered that the NFS implementation in the Linux kernel did not
properly prevent access outside of an NFS export that is a subdirectory of
a file system. An attacker could possibly use this to bypass NFS access
restrictions. (CVE-2021-3178)

Fixed packages 1

ReleasePackageFixed in
Ubuntu · 20.04 LTS 20.04:LTS linux-hwe-5.8 5.8.0-49.55~20.04.1

Vulnerabilities 5

References

  • report
    https://ubuntu.com/security/CVE-2021-3178
  • report
    https://ubuntu.com/security/CVE-2021-3347
  • report
    https://ubuntu.com/security/CVE-2021-3348
  • report
    https://ubuntu.com/security/CVE-2021-20239
  • report
    https://ubuntu.com/security/CVE-2021-20268