CVE-2021-32768: Typo3/cms core Cross-Site Scripting Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-c5c9-8c6m-727v",
  "modified" : "2024-02-07T18:51:52Z",
  "published" : "2021-08-19T15:53:12Z",
  "aliases" : [ "CVE-2021-32768" ],
  "summary" : "Cross-Site Scripting via Rich-Text Content",
  "details" : "> ### Meta\n> * CVSS: `CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC` (5.7)\n\n### Problem\nFailing to properly parse, sanitize and encode malicious rich-text content, the content rendering process in the website frontend is vulnerable to cross-site scripting. Corresponding rendering instructions via TypoScript functionality _[HTMLparser](https://docs.typo3.org/m/typo3/reference-typoscript/10.4/en-us/Functions/Htmlparser.html)_ do not consider all potentially malicious HTML tag & attribute combinations per default.\n\nIn addition, the lack of comprehensive default node configuration for rich-text fields in the backend user interface fosters this malfunction.\n\nIn default scenarios, a valid backend user account is needed to exploit this vulnerability. In case custom plugins used in the website frontend accept and reflect rich-text content submitted by users, no authentication is required.\n\n### Solution\nUpdate to TYPO3 versions 7.6.53 ELTS, 8.7.42 ELTS, 9.5.29, 10.4.19, 11.3.2 that fix the problem described above.\n\nCustom package _[typo3/html-sanitizer](https://github.com/TYPO3/html-sanitizer)_ - based on allow-lists only - takes care of sanitizing potentially malicious markup. The default behavior is based on safe and commonly used markup - however, this can be extended or restricted further in case it is necessary for individual scenarios.\n\nDuring the frontend rendering process, sanitization is applied to the default TypoScript path `lib.parseFunc`, which is implicitly used by the Fluid view-helper instruction `f:format.html`. Rich-text data persisted using the backend user interface is sanitized as well. Implementation details are explained in corresponding [ChangeLog documentation](https://docs.typo3.org/c/typo3/cms-core/master/en-us/Changelog/9.5.x/Important-94484-IntroduceHTMLSanitizer.html).\n\n### Credits\nThanks to Benjamin Stiber, Gert-Jan Jansma, Gábor Ács-Kurucz, Alexander Kellner, Richie Lee, Nina Rösch who reported this issue, and to TYPO3 security team member Oliver Hader, as well as TYPO3 contributor Susanne Moog who fixed the issue.\n\n### References\n* [TYPO3-CORE-SA-2021-013](https://typo3.org/security/advisory/typo3-core-sa-2021-013)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.6.53"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
        "fixed" : "8.7.42"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
        "fixed" : "10.4.19"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "11.0.0"
      }, {
        "fixed" : "11.3.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms-core"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.5.29"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "10.0.0"
      }, {
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    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
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  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "9.0.0"
      }, {
        "fixed" : "9.5.29"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "8.0.0"
      }, {
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    } ]
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.6.53"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/TYPO3/TYPO3.CMS/security/advisories/GHSA-c5c9-8c6m-727v"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TYPO3/typo3/security/advisories/GHSA-c5c9-8c6m-727v"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-32768"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms-core/CVE-2021-32768.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/FriendsOfPHP/security-advisories/blob/master/typo3/cms/CVE-2021-32768.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://typo3.org/security/advisory/typo3-core-sa-2021-013"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-08-16T22:38:47Z",
    "nvd_published_at" : "2021-08-10T17:15:00Z"
  }
}