Red Hat Security Advisory: kernel-rt security and bug fix update

Fixed packages 28

Vulnerabilities 4

• 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
  Jul 7, 2021

  KEV Oct 6, 2025
• High 8.7
  CVE-2021-22543

  Improper memory handling in Linux KVM

  An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to …

  Linux kernel Linux kernel linux-raspi2 linux-hwe Linux Debian Ubuntu
  May 26, 2021
• Unscored —
  CVE-2021-32399 Public exploit

  net/bluetooth/hci_request.c in the Linux kernel through 5.12.2 has a race condition for removal of the HCI controller.

  linux-raspi2 linux-hwe linux-azure linux-riscv Debian Ubuntu Azure Linux
  May 10, 2021
• Unscored —
  CVE-2021-3609

  .A flaw was found in the CAN BCM networking protocol in the Linux kernel, where a local attacker can abuse a flaw in th…

  linux-raspi2 linux-hwe linux-azure linux-riscv Debian Ubuntu
  Mar 3, 2022

References

• article
  https://access.redhat.com/security/updates/classification/#important
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=1965461
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=1970807
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=1971651
• report
  https://bugzilla.redhat.com/show_bug.cgi?id=1980101
• advisory
  https://security.access.redhat.com/data/csaf/v2/advisories/2021/rhsa-2021_3375.json
• report
  https://access.redhat.com/security/cve/CVE-2021-3609
• advisory
  https://www.cve.org/CVERecord?id=CVE-2021-3609
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2021-3609
• article
  https://www.openwall.com/lists/oss-security/2021/06/19/1
• report
  https://access.redhat.com/security/cve/CVE-2021-22543
• advisory
  https://www.cve.org/CVERecord?id=CVE-2021-22543
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2021-22543
• article
  https://github.com/google/security-research/security/advisories/GHSA-7wq5-phmq-m584
• report
  https://access.redhat.com/security/cve/CVE-2021-22555
• advisory
  https://www.cve.org/CVERecord?id=CVE-2021-22555
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2021-22555
• article
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d
• article
  https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528
• article
  https://www.cisa.gov/known-exploited-vulnerabilities-catalog
• report
  https://access.redhat.com/security/cve/CVE-2021-32399
• advisory
  https://www.cve.org/CVERecord?id=CVE-2021-32399
• advisory
  https://nvd.nist.gov/vuln/detail/CVE-2021-32399