{
  "cveId": "CVE-2021-4001",
  "url": "https://patchblox.com/security/cve/CVE-2021-4001",
  "summary": "CVE-2021-4001 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-4001, released January 21, 2022. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: A race condition was found in the Linux kernel\u0027s ebpf verifier between bpf_map_update_elem and bpf_map_freeze due to...",
  "description": "A race condition was found in the Linux kernel\u0027s 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.",
  "published": "2022-01-21T19:15:09Z",
  "severity": "medium",
  "cvss": 4.1,
  "cvssVector": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:H/A:N",
  "epss": 0.00186,
  "epssPercentile": 0.08279,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-4001",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4001",
      "released": "2022-01-21T19:15:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-4001",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4001",
      "released": "2022-01-21T19:15:09Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.15.5-1",
      "fix": "DEBIAN-CVE-2021-4001",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-4001",
      "released": "2022-01-21T19:15:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T19:12:23Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}