CVE-2021-37712 (GCVE-0-2021-37712)

Vulnerability from cvelistv5 – Published: 2021-08-31 00:00 – Updated: 2024-08-04 01:23
VLAI
Title
Arbitrary File Creation/Overwrite via insufficient symlink protection due to directory cache poisoning using symbolic links
Summary
The npm package "tar" (aka node-tar) before versions 4.4.18, 5.0.10, and 6.1.9 has an arbitrary file creation/overwrite and arbitrary code execution vulnerability. node-tar aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary stat calls to determine whether a given path is a directory, paths are cached when directories are created. This logic was insufficient when extracting tar files that contained both a directory and a symlink with names containing unicode values that normalized to the same value. Additionally, on Windows systems, long path portions would resolve to the same file system entities as their 8.3 "short path" counterparts. A specially crafted tar archive could thus include a directory with one form of the path, followed by a symbolic link with a different string that resolves to the same file system entity, followed by a file using the first form. By first creating a directory, and then replacing that directory with a symlink that had a different apparent name that resolved to the same entry in the filesystem, it was thus possible to bypass node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite. These issues were addressed in releases 4.4.18, 5.0.10 and 6.1.9. The v3 branch of node-tar has been deprecated and did not receive patches for these issues. If you are still using a v3 release we recommend you update to a more recent version of node-tar. If this is not possible, a workaround is available in the referenced GHSA-qq89-hq3f-393p.
Severity
8.2 (High)
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N
CWE
  • CWE-22 - Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
  • CWE-59 - Improper Link Resolution Before File Access ('Link Following')
Assigner
References
Impacted products
Vendor Product Version
npm node-tar Affected: < 4.4.18
Affected: >= 5.0.0, < 5.0.10
Affected: >= 6.0.0, < 6.1.9
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T01:23:01.507Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.npmjs.com/package/tar"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://github.com/npm/node-tar/security/advisories/GHSA-qq89-hq3f-393p"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
          },
          {
            "name": "DSA-5008",
            "tags": [
              "vendor-advisory",
              "x_transferred"
            ],
            "url": "https://www.debian.org/security/2021/dsa-5008"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf"
          },
          {
            "name": "[debian-lts-announce] 20221212 [SECURITY] [DLA 3237-1] node-tar security update",
            "tags": [
              "mailing-list",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/12/msg00023.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "node-tar",
          "vendor": "npm",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 4.4.18"
            },
            {
              "status": "affected",
              "version": "\u003e= 5.0.0, \u003c 5.0.10"
            },
            {
              "status": "affected",
              "version": "\u003e= 6.0.0, \u003c 6.1.9"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "The npm package \"tar\" (aka node-tar) before versions 4.4.18, 5.0.10, and 6.1.9 has an arbitrary file creation/overwrite and arbitrary code execution vulnerability. node-tar aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary stat calls to determine whether a given path is a directory, paths are cached when directories are created. This logic was insufficient when extracting tar files that contained both a directory and a symlink with names containing unicode values that normalized to the same value. Additionally, on Windows systems, long path portions would resolve to the same file system entities as their 8.3 \"short path\" counterparts. A specially crafted tar archive could thus include a directory with one form of the path, followed by a symbolic link with a different string that resolves to the same file system entity, followed by a file using the first form. By first creating a directory, and then replacing that directory with a symlink that had a different apparent name that resolved to the same entry in the filesystem, it was thus possible to bypass node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite. These issues were addressed in releases 4.4.18, 5.0.10 and 6.1.9. The v3 branch of node-tar has been deprecated and did not receive patches for these issues. If you are still using a v3 release we recommend you update to a more recent version of node-tar. If this is not possible, a workaround is available in the referenced GHSA-qq89-hq3f-393p."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 8.2,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-22",
              "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory (\u0027Path Traversal\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "CWE-59: Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-12-12T00:00:00.000Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "url": "https://www.npmjs.com/package/tar"
        },
        {
          "url": "https://github.com/npm/node-tar/security/advisories/GHSA-qq89-hq3f-393p"
        },
        {
          "url": "https://www.oracle.com/security-alerts/cpuoct2021.html"
        },
        {
          "name": "DSA-5008",
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://www.debian.org/security/2021/dsa-5008"
        },
        {
          "url": "https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf"
        },
        {
          "name": "[debian-lts-announce] 20221212 [SECURITY] [DLA 3237-1] node-tar security update",
          "tags": [
            "mailing-list"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/12/msg00023.html"
        }
      ],
      "source": {
        "advisory": "GHSA-qq89-hq3f-393p",
        "discovery": "UNKNOWN"
      },
      "title": "Arbitrary File Creation/Overwrite via insufficient symlink protection due to directory cache poisoning using symbolic links"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2021-37712",
    "datePublished": "2021-08-31T00:00:00.000Z",
    "dateReserved": "2021-07-29T00:00:00.000Z",
    "dateUpdated": "2024-08-04T01:23:01.507Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-37712",
      "date": "2026-07-21",
      "epss": "0.0185",
      "percentile": "0.76777"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-37712\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2021-08-31T17:15:08.023\",\"lastModified\":\"2024-11-21T06:15:46.193\",\"vulnStatus\":\"Modified\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"The npm package \\\"tar\\\" (aka node-tar) before versions 4.4.18, 5.0.10, and 6.1.9 has an arbitrary file creation/overwrite and arbitrary code execution vulnerability. node-tar aims to guarantee that any file whose location would be modified by a symbolic link is not extracted. This is, in part, achieved by ensuring that extracted directories are not symlinks. Additionally, in order to prevent unnecessary stat calls to determine whether a given path is a directory, paths are cached when directories are created. This logic was insufficient when extracting tar files that contained both a directory and a symlink with names containing unicode values that normalized to the same value. Additionally, on Windows systems, long path portions would resolve to the same file system entities as their 8.3 \\\"short path\\\" counterparts. A specially crafted tar archive could thus include a directory with one form of the path, followed by a symbolic link with a different string that resolves to the same file system entity, followed by a file using the first form. By first creating a directory, and then replacing that directory with a symlink that had a different apparent name that resolved to the same entry in the filesystem, it was thus possible to bypass node-tar symlink checks on directories, essentially allowing an untrusted tar file to symlink into an arbitrary location and subsequently extracting arbitrary files into that location, thus allowing arbitrary file creation and overwrite. These issues were addressed in releases 4.4.18, 5.0.10 and 6.1.9. The v3 branch of node-tar has been deprecated and did not receive patches for these issues. If you are still using a v3 release we recommend you update to a more recent version of node-tar. If this is not possible, a workaround is available in the referenced GHSA-qq89-hq3f-393p.\"},{\"lang\":\"es\",\"value\":\"El paquete npm \\\"tar\\\" (tambi\u00e9n se conoce como node-tar) versiones anteriores a 4.4.18, 5.0.10 y 6.1.9, presenta una vulnerabilidad de creaci\u00f3n y escritura excesiva de archivos arbitrarios y de ejecuci\u00f3n de c\u00f3digo arbitrario. node-tar pretende garantizar que no se extraiga ning\u00fan archivo cuya ubicaci\u00f3n ser\u00eda modificada por un enlace simb\u00f3lico. Esto es conseguido, en parte, asegurando que los directorios extra\u00eddos no sean enlaces simb\u00f3licos. Adem\u00e1s, para prevenir llamadas innecesarias a las estad\u00edsticas para determinar si una ruta dada es un directorio, las rutas son almacenadas en cach\u00e9 cuando se crean los directorios. Esta l\u00f3gica era insuficiente cuando se extra\u00edan archivos tar que conten\u00edan tanto un directorio como un enlace simb\u00f3lico con nombres que conten\u00edan valores unicode que se normalizaban al mismo valor. Adem\u00e1s, en los sistemas Windows, las partes de la ruta larga se resolv\u00edan a las mismas entidades del sistema de archivos que sus hom\u00f3logos de la \\\"ruta corta\\\" de la versi\u00f3n 8.3. Un archivo tar especialmente dise\u00f1ado podr\u00eda incluir un directorio con una forma de la ruta, seguido de un enlace simb\u00f3lico con una cadena diferente que resuelve a la misma entidad del sistema de archivos, seguido de un archivo usando la primera forma. Al crear primero un directorio, y luego reemplazando ese directorio con un enlace simb\u00f3lico que tuviera un nombre aparente diferente que resolviera a la misma entrada en el sistema de archivos, era posible as\u00ed omitir las comprobaciones de enlaces simb\u00f3licos de node-tar en los directorios, permitiendo esencialmente que un archivo tar no confiable tuviera un enlace simb\u00f3lico en una ubicaci\u00f3n arbitraria y que posteriormente extrajera archivos arbitrarios en esa ubicaci\u00f3n, permitiendo as\u00ed la creaci\u00f3n y escritura excesiva arbitraria de archivos. Estos problemas se solucionaron en las versiones 4.4.18, 5.0.10 y 6.1.9. La rama v3 de node-tar ha quedado obsoleta y no ha recibido parches para estos problemas. Si todav\u00eda est\u00e1 usando una versi\u00f3n v3, le recomendamos que actualice a una versi\u00f3n m\u00e1s reciente de node-tar. Si esto no es posible, hay una soluci\u00f3n disponible en la referencia GHSA-qq89-hq3f-393p\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N\",\"baseScore\":8.2,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":1.8,\"impactScore\":5.8},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H\",\"baseScore\":8.6,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"REQUIRED\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":6.0}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:L/AC:M/Au:N/C:P/I:P/A:P\",\"baseScore\":4.4,\"accessVector\":\"LOCAL\",\"accessComplexity\":\"MEDIUM\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"PARTIAL\",\"integrityImpact\":\"PARTIAL\",\"availabilityImpact\":\"PARTIAL\"},\"baseSeverity\":\"MEDIUM\",\"exploitabilityScore\":3.4,\"impactScore\":6.4,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":true}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-22\"},{\"lang\":\"en\",\"value\":\"CWE-59\"}]},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-59\"}]}],\"configurations\":[{\"operator\":\"AND\",\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*\",\"versionEndIncluding\":\"4.4.17\",\"matchCriteriaId\":\"397B3C13-8279-4658-9B02-7217671EE55F\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*\",\"versionStartIncluding\":\"5.0.0\",\"versionEndIncluding\":\"5.0.9\",\"matchCriteriaId\":\"F925F5A7-30FC-4EF0-AA6F-0E65BFD2FA0A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:npmjs:tar:*:*:*:*:*:node.js:*:*\",\"versionStartIncluding\":\"6.0.0\",\"versionEndIncluding\":\"6.1.8\",\"matchCriteriaId\":\"02ED32D1-9BBB-4E6F-9AA0-E48B4232BF1C\"}]},{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":false,\"criteria\":\"cpe:2.3:o:microsoft:windows:-:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"A2572D17-1DE6-457B-99CC-64AFD54487EA\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"07B237A9-69A3-4A9C-9DA0-4E06BD37AE73\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*\",\"matchCriteriaId\":\"FA6FEEC2-9F11-4643-8827-749718254FED\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:oracle:graalvm:20.3.3:*:*:*:enterprise:*:*:*\",\"matchCriteriaId\":\"53B2BB06-A2F7-4603-89C3-C8500E55483A\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:oracle:graalvm:21.2.0:*:*:*:enterprise:*:*:*\",\"matchCriteriaId\":\"01E88C86-8C04-4A4A-BF45-9082AA783056\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:siemens:sinec_infrastructure_network_services:*:*:*:*:*:*:*:*\",\"versionEndExcluding\":\"1.0.1.1\",\"matchCriteriaId\":\"B0F46497-4AB0-49A7-9453-CC26837BF253\"}]}]}],\"references\":[{\"url\":\"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/npm/node-tar/security/advisories/GHSA-qq89-hq3f-393p\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2022/12/msg00023.html\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://www.debian.org/security/2021/dsa-5008\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.npmjs.com/package/tar\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Product\"]},{\"url\":\"https://www.oracle.com/security-alerts/cpuoct2021.html\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://github.com/npm/node-tar/security/advisories/GHSA-qq89-hq3f-393p\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]},{\"url\":\"https://lists.debian.org/debian-lts-announce/2022/12/msg00023.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://www.debian.org/security/2021/dsa-5008\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\"]},{\"url\":\"https://www.npmjs.com/package/tar\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Product\"]},{\"url\":\"https://www.oracle.com/security-alerts/cpuoct2021.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Patch\",\"Third Party Advisory\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T06:52:38+00:00",
      "cve": "CVE-2021-37712",
      "id": "CVE-2021-37712",
      "initial_release_date": "2021-08-31T00:00:00+00:00",
      "product_status:fixed": "257",
      "product_status:known_affected": "12",
      "product_status:known_not_affected": "26",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "nodejs-tar: Insufficient symlink protection due to directory cache poisoning using symbolic links allowing arbitrary file creation and overwrite",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-37712.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.