{
  "id": "CVE-2021-22555",
  "url": "https://spydr.io/cve/CVE-2021-22555",
  "published": "2021-07-07T12:15:08.453Z",
  "modified": "2026-06-17T03:37:25.510Z",
  "score": 7.8,
  "severity": "high",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.78684,
  "epss_percentile": 0.9958,
  "exploited": true,
  "kev": {
    "added": "2025-10-06",
    "due": "2025-10-27",
    "action": "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.",
    "ransomware": "Unknown",
    "name": "Linux Kernel Heap Out-of-Bounds Write Vulnerability",
    "notes": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21 ; https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d ; https://security.netapp.com/advisory/ntap-20210805-0010/ ; https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528 ; https://nvd.nist.gov/vuln/detail/CVE-2021-22555"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "netapp",
    "linux",
    "brocade"
  ],
  "products": [
    "Linux Kernel"
  ],
  "cwes": [
    "CWE-787"
  ],
  "description": "A heap out-of-bounds write affecting Linux since v2.6.19-rc1 was discovered in net/netfilter/x_tables.c. This allows an attacker to gain privileges or cause a DoS (via heap memory corruption) through user name space",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 7.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://packetstormsecurity.com/files/163528/Linux-Kernel-Netfilter-Heap-Out-Of-Bounds-Write.html",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/163878/Kernel-Live-Patch-Security-Notice-LSN-0080-1.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164155/Kernel-Live-Patch-Security-Notice-LSN-0081-1.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/164437/Netfilter-x_tables-Heap-Out-Of-Bounds-Write-Privilege-Escalation.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/165477/Kernel-Live-Patch-Security-Notice-LSN-0083-1.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=9fa492cdc160cd27ce1046cb36f47d3b2b1efa21",
      "tags": [
        "Mailing List",
        "Patch",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/netfilter/x_tables.c?id=b29c457a6511435960115c0f548c4360d5f4801d",
      "tags": [
        "Mailing List",
        "Patch",
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://github.com/google/security-research/security/advisories/GHSA-xxx5-8mvq-3528",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://security.netapp.com/advisory/ntap-20210805-0010/",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22555",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2021-22555",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}