{
  "schema_version": "1.4.0",
  "id": "GHSA-c6xj-3c77-g5rg",
  "modified": "2022-05-13T01:19:42Z",
  "published": "2022-05-13T01:19:42Z",
  "aliases": [
    "CVE-2018-18955"
  ],
  "details": "In the Linux kernel 4.15.x through 4.19.x before 4.19.2, map_write() in kernel/user_namespace.c allows privilege escalation because it mishandles nested user namespaces with more than 5 UID or GID ranges. A user who has CAP_SYS_ADMIN in an affected user namespace can bypass access controls on resources outside the namespace, as demonstrated by reading /etc/shadow. This occurs because an ID transformation takes place properly for the namespaced-to-kernel direction but not for the kernel-to-namespaced direction.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-18955"
    },
    {
      "type": "WEB",
      "url": "https://github.com/torvalds/linux/commit/d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd"
    },
    {
      "type": "WEB",
      "url": "https://bugs.chromium.org/p/project-zero/issues/detail?id=1712"
    },
    {
      "type": "WEB",
      "url": "https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.19"
    },
    {
      "type": "WEB",
      "url": "https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.2"
    },
    {
      "type": "WEB",
      "url": "https://security.netapp.com/advisory/ntap-20190416-0003"
    },
    {
      "type": "WEB",
      "url": "https://support.f5.com/csp/article/K39103040"
    },
    {
      "type": "WEB",
      "url": "https://usn.ubuntu.com/3832-1"
    },
    {
      "type": "WEB",
      "url": "https://usn.ubuntu.com/3833-1"
    },
    {
      "type": "WEB",
      "url": "https://usn.ubuntu.com/3835-1"
    },
    {
      "type": "WEB",
      "url": "https://usn.ubuntu.com/3836-1"
    },
    {
      "type": "WEB",
      "url": "https://usn.ubuntu.com/3836-2"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/45886"
    },
    {
      "type": "WEB",
      "url": "https://www.exploit-db.com/exploits/45915"
    },
    {
      "type": "WEB",
      "url": "http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d2f007dbe7e4c9583eea6eb04d60001e85c6f1bd"
    },
    {
      "type": "WEB",
      "url": "http://www.securityfocus.com/bid/105941"
    }
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "severity": "HIGH",
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2018-11-16T20:29:00Z"
  }
}