First published: Sun Sep 12 2021(Updated: )
An unprivileged write to the file handler flaw in the Linux kernel's control groups and namespaces subsystem was found in the way users have access to some less privileged process that are controlled by cgroups and have higher privileged parent process. It is actually both for cgroup2 and cgroup1 versions of control groups. A local user could use this flaw to crash the system or escalate their privileges on the system.
Credit: secalert@redhat.com
Affected Software | Affected Version | How to fix |
---|---|---|
redhat/kernel-rt | <0:4.18.0-372.9.1.rt7.166.el8 | 0:4.18.0-372.9.1.rt7.166.el8 |
redhat/kernel | <0:4.18.0-372.9.1.el8 | 0:4.18.0-372.9.1.el8 |
redhat/kernel-rt | <0:4.18.0-305.57.1.rt7.129.el8_4 | 0:4.18.0-305.57.1.rt7.129.el8_4 |
redhat/kernel | <0:4.18.0-305.57.1.el8_4 | 0:4.18.0-305.57.1.el8_4 |
redhat/Linux kernel | <5.17 | 5.17 |
Linux Kernel | >=4.2<4.14.276 | |
Linux Kernel | >=4.15<4.19.238 | |
Linux Kernel | >=4.20<5.4.189 | |
Linux Kernel | >=5.5<5.10.111 | |
Linux Kernel | >=5.11<5.15.14 | |
oracle communications Cloud native core binding support function | =22.1.1 | |
oracle communications Cloud native core binding support function | =22.1.3 | |
oracle communications Cloud native core binding support function | =22.2.0 | |
Debian GNU/Linux | =10.0 | |
broadcom brocade fabric operating system firmware | ||
All of | ||
netapp h300s firmware | ||
netapp h300s | ||
All of | ||
NetApp H500S Firmware | ||
netapp h500s | ||
All of | ||
netapp h700s firmware | ||
netapp h700s | ||
All of | ||
netapp h410s firmware | ||
netapp h410s | ||
All of | ||
netapp h410c firmware | ||
netapp h410c | ||
netapp h300s firmware | ||
netapp h300s | ||
NetApp H500S Firmware | ||
netapp h500s | ||
netapp h700s firmware | ||
netapp h700s | ||
netapp h410s firmware | ||
netapp h410s | ||
netapp h410c firmware | ||
netapp h410c | ||
debian/linux | 5.10.223-1 5.10.226-1 6.1.123-1 6.1.128-1 6.12.12-1 6.12.15-1 |
The mitigation not known. However, for the default configuration of the Red Hat Enterprise Linux it is not possible to trigger this vulnerability: if control groups (cgroups) not being used or being used with the default configuration or being used some other configuration where for example similar privileges for all processes (both for parent and for child processes), then no way to trigger this vulnerability.
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(Appears in the following advisories)
CVE-2021-4197 has a high severity rating due to the potential for unprivileged users to write to file handlers controlled by cgroups.
CVE-2021-4197 affects Linux kernel versions up to 4.18.0-372.9.1 and various versions within the 4.x series up to 5.x.
To fix CVE-2021-4197, update your Linux kernel to the specified remedied versions for your distribution as indicated in the security advisories.
CVE-2021-4197 requires local access to exploit, which means it cannot be directly exploited remotely.
The potential impacts of CVE-2021-4197 include unauthorized access to file handlers and potential privilege escalation for unprivileged processes.