{
  "cveId": "CVE-2021-47010",
  "url": "https://patchblox.com/security/cve/CVE-2021-47010",
  "summary": "CVE-2021-47010 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47010, released February 28, 2024. It is not reported as exploited. Patch Radar priority: High.",
  "title": "linux: In the Linux kernel, the following vulnerability has been resolved:  net: Only allow init netns to set default tcp co...",
  "description": "In the Linux kernel, the following vulnerability has been resolved:  net: Only allow init netns to set default tcp cong to a restricted algo  tcp_set_default_congestion_control() is netns-safe in that it writes to \u0026net-\u003Eipv4.tcp_congestion_control, but it also sets ca-\u003Eflags |= TCP_CONG_NON_RESTRICTED which is not namespaced. This has the unintended side-effect of changing the global net.ipv4.tcp_allowed_congestion_control sysctl, despite the fact that it is read-only: 97684f0970f6 (\u0022net: Make tcp_allowed_congestion_control readonly in non-init netns\u0022)  Resolve this netns \u0022leak\u0022 by only allowing the init netns to set the default algorithm to one that is restricted. This restriction could be removed if tcp_allowed_congestion_control were namespace-ified in the future.  This bug was uncovered with https://github.com/JonathonReinhart/linux-netns-sysctl-verify",
  "published": "2024-02-28T09:15:38Z",
  "severity": "high",
  "cvss": 7.8,
  "cvssVector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.00257,
  "epssPercentile": 0.17474,
  "priority": "High",
  "priorityTier": 3,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "5.10.38-1",
      "fix": "DEBIAN-CVE-2021-47010",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47010",
      "released": "2024-02-28T09:15:38Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "5.10.38-1",
      "fix": "DEBIAN-CVE-2021-47010",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47010",
      "released": "2024-02-28T09:15:38Z"
    },
    {
      "platform": "linux",
      "product": "linux",
      "release": "Debian 14",
      "fixedVersion": "5.10.38-1",
      "fix": "DEBIAN-CVE-2021-47010",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-47010",
      "released": "2024-02-28T09:15:38Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T06:59:42Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}