{
  "document": {
    "aggregate_severity": {
      "text": "Critical"
    },
    "category": "csaf_vex",
    "csaf_version": "2.0",
    "distribution": {
      "text": "TuxCare License Agreement",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "legal_disclaimer",
        "text": "This content is licensed under the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/). If you distribute this content, or a modified version of it, you must provide attribution to Cloud Linux Inc. and provide a link to the original.",
        "title": "Terms of Use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://tuxcare.com/contact/",
      "name": "TuxCare",
      "namespace": "https://tuxcare.com/"
    },
    "references": [
      {
        "category": "self",
        "summary": "Canonical URL",
        "url": "https://security.tuxcare.com/csaf/v2/els_os/ubuntu16.04els/vex/2018/cve-2018-7548-els_os-ubuntu16_04els.json"
      }
    ],
    "tracking": {
      "current_release_date": "2026-04-24T11:49:54Z",
      "generator": {
        "date": "2026-04-24T11:49:54Z",
        "engine": {
          "name": "pyCSAF"
        }
      },
      "id": "CVE-2018-7548-ELS_OS-UBUNTU16.04ELS",
      "initial_release_date": "2018-02-27T22:29:00Z",
      "revision_history": [
        {
          "date": "2018-02-27T22:29:00Z",
          "number": "1",
          "summary": "Initial version"
        },
        {
          "date": "2026-04-20T15:27:18Z",
          "number": "2",
          "summary": "Official Publication"
        },
        {
          "date": "2026-04-24T11:49:54Z",
          "number": "3",
          "summary": "Update document"
        }
      ],
      "status": "final",
      "version": "3"
    },
    "title": "Security update on CVE-2018-7548"
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_name",
                "name": "Ubuntu 16.04",
                "product": {
                  "name": "Ubuntu 16.04",
                  "product_id": "Ubuntu-16",
                  "product_identification_helper": {
                    "cpe": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:lts:*:*:*"
                  }
                }
              }
            ],
            "category": "product_family",
            "name": "Ubuntu"
          }
        ],
        "category": "vendor",
        "name": "Canonical Ltd."
      },
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all",
                "product": {
                  "name": "zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all",
                  "product_id": "zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all",
                  "product_identification_helper": {
                    "purl": "pkg:deb/tuxcare/zsh-common@5.1.1-1ubuntu2.3%2Btuxcare.els1?arch=all"
                  }
                }
              }
            ],
            "category": "architecture",
            "name": "all"
          }
        ],
        "category": "vendor",
        "name": "TuxCare"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all as a component of Ubuntu 16.04",
          "product_id": "Ubuntu-16:zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all"
        },
        "product_reference": "zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all",
        "relates_to_product_reference": "Ubuntu-16"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2018-7548",
      "cwe": {
        "id": "CWE-476",
        "name": "NULL Pointer Dereference"
      },
      "notes": [
        {
          "category": "description",
          "text": "In subst.c in zsh through 5.4.2, there is a NULL pointer dereference when using ${(PA)...} on an empty array result.",
          "title": "Vulnerability description"
        },
        {
          "category": "general",
          "text": "The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.",
          "title": "CVSS score applicability"
        },
        {
          "category": "other",
          "text": "TuxCare has assessed that this vulnerability does not impact any currently supported TuxCare products. This evaluation may change as new information becomes available. For additional details regarding this vulnerability and affected products, refer to the provided references.",
          "title": "Statement"
        }
      ],
      "product_status": {
        "known_not_affected": [
          "Ubuntu-16:zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "Canonical URL",
          "url": "https://cve.tuxcare.com/els/cve/CVE-2018-7548"
        },
        {
          "category": "external",
          "summary": "https://security.gentoo.org/glsa/201805-10",
          "url": "https://security.gentoo.org/glsa/201805-10"
        },
        {
          "category": "external",
          "summary": "https://sourceforge.net/p/zsh/code/ci/110b13e1090bc31ac1352b28adc2d02b6d25a102",
          "url": "https://sourceforge.net/p/zsh/code/ci/110b13e1090bc31ac1352b28adc2d02b6d25a102"
        },
        {
          "category": "external",
          "summary": "https://usn.ubuntu.com/3593-1/",
          "url": "https://usn.ubuntu.com/3593-1/"
        }
      ],
      "release_date": "2018-02-27T22:29:00Z",
      "scores": [
        {
          "cvss_v2": {
            "accessComplexity": "LOW",
            "accessVector": "NETWORK",
            "authentication": "NONE",
            "availabilityImpact": "PARTIAL",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "PARTIAL",
            "integrityImpact": "PARTIAL",
            "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
            "version": "2.0"
          },
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.0"
          },
          "products": [
            "Ubuntu-16:zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Critical"
        },
        {
          "category": "impact",
          "details": "critical",
          "product_ids": [
            "Ubuntu-16:zsh-common-0:5.1.1-1ubuntu2.3+tuxcare.els1.all"
          ]
        }
      ]
    }
  ]
}