synced 13 MIN AGO
01 Record

CVE-2021-4001

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

UnratedPUBLISHEDCNA: redhat
CNA base scoreUnratedNo CNA CVSS vector

02 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

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.18% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 7.8% of scored records. A rank, not a probability.
NVD base score
4.1 (CVSS v3.x), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N
NVD analysis status
Modified. NVD last modified this record on 2026-10-08.
Red Hat severity
Moderate. Red Hat's rating for its own products, not a CVSS rating.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2022-01-21 00:00Z4 YR AGO
Last updated
2026-10-08 21:03Z21 DAYS AGO
Reserved
2021-11-22
Assigning CNA
redhat
Record state
PUBLISHED
Severity
Not rated by the issuing CNA
CNA CVSS vector
Not published by the issuing CNA
Weaknesses
  • CWE-367Time-of-check Time-of-use (TOCTOU) Race ConditionBase
Data version
5.2
Document digest
b2d2b5ddf7dbcff5ecf7be7d010a7a0f06b496b3eae0aa1241901e26b100269f

05 Affected products

VendorProductVersionsPlatforms
n/akernelkernel 5.16 rc2—

06 References

07 Fixed in

Arch Linux

  • linux
    Fixed in 5.15.5.arch1-1
  • linux-hardened
    Fixed in 5.15.5.hardened1-1
  • linux-lts
    Fixed in 5.10.83-1
  • linux-zen
    Fixed in 5.15.5.zen1-1

Source: Arch Linux Security Tracker, the Arch Linux security team. Reformatted by exploit.cc.

Debian 12

  • linux
    Fixed in 5.15.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 13

  • linux
    Fixed in 5.15.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Debian 14

  • linux
    Fixed in 5.15.5-1

Source: Debian Security Tracker, the Debian security team. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 16.04 LTS

  • linux-hwe-edge
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 18.04 LTS

  • linux-aws-5.0
    No fix yet
  • linux-aws-5.3
    No fix yet
  • linux-azure
    No fix yet
  • linux-azure-5.3
    No fix yet
  • linux-azure-edge
    No fix yet
  • linux-gcp
    No fix yet
  • linux-gcp-5.3
    No fix yet
  • linux-gke-4.15
    No fix yet
  • linux-gke-5.4
    No fix yet
  • linux-gkeop-5.4
    No fix yet
  • linux-hwe
    No fix yet
  • linux-oem
    No fix yet
  • linux-oracle-5.0
    No fix yet
  • linux-oracle-5.3
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 20.04 LTS

  • linux
    Fixed in 5.4.0-164.181
  • linux-aws
    Fixed in 5.4.0-1111.120
  • linux-aws-5.11
    Fixed in 5.11.0-1028.31~20.04.1
  • linux-aws-5.13
    Fixed in 5.13.0-1012.13~20.04.1
  • linux-aws-5.8
    No fix yet
  • linux-azure
    Fixed in 5.4.0-1117.124
  • linux-azure-5.11
    Fixed in 5.11.0-1028.31~20.04.2
  • linux-azure-5.13
    Fixed in 5.13.0-1013.15~20.04.1
  • linux-azure-5.8
    No fix yet
  • linux-azure-fde
    No fix yet
  • linux-bluefield
    Fixed in 5.4.0-1072.78
  • linux-gcp
    Fixed in 5.4.0-1115.124
  • linux-gcp-5.11
    Fixed in 5.11.0-1029.33~20.04.3
  • linux-gcp-5.13
    Fixed in 5.13.0-1013.16~20.04.1
  • linux-gcp-5.8
    No fix yet
  • linux-gke
    No fix yet
  • linux-gkeop
    Fixed in 5.4.0-1078.82
  • linux-hwe-5.11
    No fix yet
  • linux-hwe-5.13
    Fixed in 5.13.0-28.31~20.04.1
  • linux-hwe-5.8
    No fix yet
  • linux-ibm
    Fixed in 5.4.0-1058.63
  • linux-intel-5.13
    No fix yet
  • linux-iot
    Fixed in 5.4.0-1023.24
  • linux-kvm
    Fixed in 5.4.0-1100.106
  • linux-oem-5.10
    Fixed in 5.10.0-1053.55
  • linux-oem-5.13
    Fixed in 5.13.0-1029.36
  • linux-oem-5.14
    Fixed in 5.14.0-1022.24
  • linux-oem-5.6
    No fix yet
  • linux-oracle
    Fixed in 5.4.0-1110.119
  • linux-oracle-5.11
    Fixed in 5.11.0-1028.31~20.04.1
  • linux-oracle-5.13
    Fixed in 5.13.0-1016.20~20.04.1
  • linux-oracle-5.8
    No fix yet
  • linux-raspi
    Fixed in 5.4.0-1095.106
  • linux-raspi2
    No fix yet
  • linux-riscv
    No fix yet
  • linux-riscv-5.11
    No fix yet
  • linux-riscv-5.8
    No fix yet
  • linux-xilinx-zynqmp
    Fixed in 5.4.0-1031.35

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 22.04 LTS

  • linux-intel-iot-realtime
    No fix yet
  • linux-realtime
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu 24.04 LTS

  • linux-raspi-realtime
    No fix yet

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro 18.04 LTS

  • linux-aws-5.4
    Fixed in 5.4.0-1111.120~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-azure-5.4
    Fixed in 5.4.0-1117.124~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-gcp-5.4
    Fixed in 5.4.0-1115.124~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-hwe-5.4
    Fixed in 5.4.0-164.181~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-ibm-5.4
    Fixed in 5.4.0-1058.63~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-oracle-5.4
    Fixed in 5.4.0-1110.119~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
  • linux-raspi-5.4
    Fixed in 5.4.0-1095.106~18.04.1
    Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

Ubuntu Pro FIPS-updates 20.04 LTS

  • linux-aws-fips
    Fixed in 5.4.0-1111.120+fips1
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-azure-fips
    Fixed in 5.4.0-1117.124+fips1
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-fips
    Fixed in 5.4.0-1086.95
    Available with Ubuntu Pro: https://ubuntu.com/pro
  • linux-gcp-fips
    Fixed in 5.4.0-1115.124+fips1
    Available with Ubuntu Pro: https://ubuntu.com/pro

Source: Ubuntu, Canonical Ltd. Licensed under CC BY-SA 4.0. Received through OSV.dev. Reformatted by exploit.cc.

A release or ecosystem missing from this list has no record here. It may be unaffected or not covered by the source. Source notices and licences.