CVE-2021-4001

Description

A race condition was found in the Linux kernel's ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to a missing lock in kernel/bpf/syscall.c. In this flaw, a local user with a special privilege (cap_sys_admin or cap_bpf) can modify the frozen mapped address space. This flaw affects kernel versions prior to 5.16 rc2.

Category

4.1
CVSS
Severity: Medium
CVSS 3.1 •
CVSS 2.0 •
EPSS 0.01%
Third-Party Advisory redhat.com Third-Party Advisory kernel.org
Affected: n/a kernel
Published at:
Updated at:

References

Link Tags
https://bugzilla.redhat.com/show_bug.cgi?id=2025645 patch third party advisory issue tracking
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53 third party advisory patch

Frequently Asked Questions

What is the severity of CVE-2021-4001?
CVE-2021-4001 has been scored as a medium severity vulnerability.
How to fix CVE-2021-4001?
To fix CVE-2021-4001, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-4001 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-4001 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-4001?
CVE-2021-4001 affects n/a kernel.
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