{
  "cveId": "CVE-2021-47452",
  "url": "https://patchblox.com/security/cve/CVE-2021-47452",
  "summary": "CVE-2021-47452 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47452, released May 22, 2024. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  netfilter: nf_tables: skip netdev events generat...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  netfilter: nf_tables: skip netdev events generated on netns removal  syzbot reported following (harmless) WARN:   WARNING: CPU: 1 PID: 2648 at net/netfilter/core.c:468   nft_netdev_unregister_hooks net/netfilter/nf_tables_api.c:230 [inline]   nf_tables_unregister_hook include/net/netfilter/nf_tables.h:1090 [inline]   __nft_release_basechain\u002B0x138/0x640 net/netfilter/nf_tables_api.c:9524   nft_netdev_event net/netfilter/nft_chain_filter.c:351 [inline]   nf_tables_netdev_event\u002B0x521/0x8a0 net/netfilter/nft_chain_filter.c:382  reproducer: unshare -n bash -c \u0027ip link add br0 type bridge; nft add table netdev t ; \\  nft add chain netdev t ingress \\{ type filter hook ingress device \u0022br0\u0022 \\  priority 0\\; policy drop\\; \\}\u0027  Problem is that when netns device exit hooks create the UNREGISTER event, the .pre_exit hook for nf_tables core has already removed the base hook.  Notifier attempts to do this again.  The need to do base hook unregister unconditionally was needed in the past, because notifier was last stage where reg-\u003Edev dereference was safe.  Now that nf_tables does the hook removal in .pre_exit, this isn\u0027t needed anymore.",
  "published": "2024-05-22T07:15:10Z",
  "severity": "medium",
  "cvss": 5.5,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
  "epss": 0.00196,
  "epssPercentile": 0.09372,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47452",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47452",
      "released": "2024-05-22T07:15:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47452",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47452",
      "released": "2024-05-22T07:15:10Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.14.16-1",
      "fix": "DEBIAN-CVE-2021-47452",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47452",
      "released": "2024-05-22T07:15:10Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T01:18:40Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}