CVE-2021-4001
Summary
| CVE | CVE-2021-4001 |
|---|---|
| State | PUBLISHED |
| Assigner | redhat |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2022-01-21 19:15:09 UTC |
| Updated | 2026-10-08 21:17:42 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 4.1 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
EPSS: 0.001860000 probability, percentile 0.075800000 (date 2026-10-10)
Problem Types: CWE-367 | CWE-367 CWE-367
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 4.1 | MEDIUM | CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N |
| 2.0 | [email protected] | Primary | 4.7 | AV:L/AC:M/Au:N/C:N/I:C/A:N |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
HighPrivileges Required
HighUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
HighAvailability
NoneCVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
CVSS v2.0 Breakdown
Access Vector
LocalAccess Complexity
MediumAuthentication
NoneConfidentiality
NoneIntegrity
CompleteAvailability
NoneAV:L/AC:M/Au:N/C:N/I:C/A:N
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | 5.16 | rc1 | All | All |
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| 2025645 – (CVE-2021-4001) CVE-2021-4001 kernel: race condition when the EBPF map is frozen | af854a3a-2127-422b-91ae-364da2661108 | bugzilla.redhat.com | Issue Tracking, Patch, Third Party Advisory |
| kernel/git/bpf/bpf.git - BPF kernel tree | af854a3a-2127-422b-91ae-364da2661108 | git.kernel.org | Patch, Third Party Advisory |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
Legacy QID Mappings
- 180355 Debian Security Update for linux (CVE-2021-4001)
- 198616 Ubuntu Security Notification for Linux kernel (OEM) Vulnerabilities (USN-5207-1)
- 198653 Ubuntu Security Notification for Linux kernel Vulnerabilities (USN-5265-1)
- 198659 Ubuntu Security Notification for Linux kernel (OEM) Vulnerabilities (USN-5278-1)
- 199804 Ubuntu Security Notification for Linux kernel Vulnerabilities (USN-6417-1)
- 282087 Fedora Security Update for kernel (FEDORA-2021-c0dc424b7d)
- 282133 Fedora Security Update for kernel (FEDORA-2021-19ad835cb3)
- 353141 Amazon Linux Security Advisory for kernel : ALAS2KERNEL-5.4-2022-010
- 353152 Amazon Linux Security Advisory for kernel : ALAS2KERNEL-5.10-2022-008
- 751590 OpenSUSE Security Update for the Linux Kernel (openSUSE-SU-2022:0056-1)
- 751622 OpenSUSE Security Update for the Linux Kernel (openSUSE-SU-2022:0131-1)
- 751654 SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2022:0197-1)
- 751989 SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2022:0131-1)
- 753132 SUSE Enterprise Linux Security Update for the Linux Kernel (Live Patch 2 for SLE 15 SP3) (SUSE-SU-2022:0978-1)
- 753133 SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2022:0181-1)
- 753264 SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2022:0079-1)
- 753355 SUSE Enterprise Linux Security Update for the Linux Kernel (SUSE-SU-2022:0056-1)
- 753487 SUSE Enterprise Linux Security Update for the Linux Kernel (Live Patch 10 for SLE 15 SP3) (SUSE-SU-2022:0984-1)
- 900617 Common Base Linux Mariner (CBL-Mariner) Security Update for kernel (8322)
- 905851 Common Base Linux Mariner (CBL-Mariner) Security Update for kernel (8322-1)