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
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.
- 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
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 5.4.0-1111.120~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-azure-5.4 Fixed in 5.4.0-1117.124~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-gcp-5.4 Fixed in 5.4.0-1115.124~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-hwe-5.4 Fixed in 5.4.0-164.181~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-ibm-5.4 Fixed in 5.4.0-1058.63~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-oracle-5.4 Fixed in 5.4.0-1110.119~18.04.1Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro
- linux-raspi-5.4 Fixed in 5.4.0-1095.106~18.04.1Available 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+fips1Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-azure-fips Fixed in 5.4.0-1117.124+fips1Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-fips Fixed in 5.4.0-1086.95Available with Ubuntu Pro: https://ubuntu.com/pro
- linux-gcp-fips Fixed in 5.4.0-1115.124+fips1Available 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.