CVE-2021-4001CWE-367

CVE-2021-4001

Medium · published January 22, 2022

CVSS v3.1
4.1
EPSS
0%
Percentile
7.8
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
4.1 · MEDIUM
Vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
CVSS v4.0
Not supplied
EPSS
0.00186 · 7.8th percentile
Weakness
CWE-367 · Time-of-check Time-of-use (TOCTOU) Race Condition
Published
2022-01-22T00:15Z
Affected products (2)
ProductVersionsFixed in
linux/linux_kernel≤ 5.15—
linux/linux_kernelall versions—
References (4)
https://bugzilla.redhat.com/show_bug.cgi?id=2025645 · [email protected]https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53 · [email protected]https://bugzilla.redhat.com/show_bug.cgi?id=2025645 · af854a3a-2127-422b-91ae-364da2661108https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git/commit/?id=353050be4c19e102178ccc05988101887c25ae53 · af854a3a-2127-422b-91ae-364da2661108
EPSS history
Timeline
  • 21 JAN 00:00Z
    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
    cvelistv5