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OpenAdvisories
High 1 exploited CVE LSN-0080-1 1 CVE

Kernel Live Patch Security Notice

Published Aug 16, 2021 · Updated Jun 3, 2026

Ecosystem: Ubuntu

Summary

Andy Nguyen discovered that the netfilter subsystem in the Linux kernel
contained an out-of-bounds write in its setsockopt() implementation. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code.(CVE-2021-22555)

Fixed packages 13

ReleasePackageFixed in
Ubuntu · Pro 14.04 LTS Pro:14.04:LTS linux-lts-xenial 4.4.0-213.245~14.04.1
Ubuntu · Pro 16.04 LTS Pro:16.04:LTS linux 4.4.0-213.245
Ubuntu · Pro 16.04 LTS Pro:16.04:LTS linux-hwe 4.15.0-144.148~16.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux 4.15.0-144.148
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-gke-4.15 —
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-gke-5.4 5.4.0-1044.46~18.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-gkeop-5.4 5.4.0-1016.17~18.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-hwe-5.4 5.4.0-74.83~18.04.1
Ubuntu · Pro 18.04 LTS Pro:18.04:LTS linux-oem —
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux 5.4.0-74.83
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gcp 5.4.0-1044.47
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gke 5.4.0-1044.46
Ubuntu · Pro 20.04 LTS Pro:20.04:LTS linux-gkeop 5.4.0-1016.17

Vulnerabilities 1

  • High 8.3
    CVE-2021-22555 Exploited Public exploit EPSS 79%

    Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE

    A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space

    linux-raspi2 linux-hwe linux-azure linux-riscv Linux Debian Ubuntu
    KEV Oct 6, 2025

References

  • report
    https://ubuntu.com/security/CVE-2021-22555