{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2021-21387",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2021-21387",
    "idYear": 2021,
    "status": "PUBLISHED",
    "publishedAt": "2021-03-19T15:25:12.000Z",
    "updatedAt": "2024-08-03T18:09:15.979Z",
    "importedAt": "2026-10-24T01:56:26.894Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "Partial secret key disclosure, improper safety number calculation, & inadequate encryption strength",
      "summary": "Wrongthink peer-to-peer, end-to-end encrypted messenger with PeerJS and Axolotl ratchet. In wrongthink from version 2.0.0 and before 2.3.0 there was a set of vulnerabilities causing inadequate encryption strength. Part of the secret identity key was disclosed by the fingerprint used for connection. Additionally, the safety number was improperly calculated. It was computed using part of one of the public identity keys instead of being derived from both public identity keys. This caused issues in computing safety numbers which would potentially be exploitable in the real world. Additionally there was inadequate encryption strength due to use of 1024-bit DSA keys. These issues are all fixed in version 2.3.0.",
      "affected": [
        {
          "vendor": "parabirb",
          "product": "wrongthink",
          "versions": [
            {
              "version": ">= 2.0.0, < 2.2.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  }
}