{
  "schema_version": "1.5.0",
  "id": "CURL-CVE-2021-22925",
  "aliases": [
    "CVE-2021-22925"
  ],
  "summary": "TELNET stack contents disclosure again",
  "modified": "2026-04-25T17:48:46.00Z",
  "database_specific": {
    "package": "curl",
    "affects": "both",
    "URL": "https://curl.se/docs/CVE-2021-22925.json",
    "www": "https://curl.se/docs/CVE-2021-22925.html",
    "issue": "https://hackerone.com/reports/1223882",
    "CWE": {
      "id": "CWE-457",
      "desc": "Use of Uninitialized Variable"
    },
    "award": {
      "amount": "800",
      "currency": "USD"
    },
    "last_affected": "7.77.0",
    "severity": "Medium"
  },
  "published": "2021-07-21T08:00:00.00Z",
  "affected": [
    {
      "ranges": [
        {
           "type": "SEMVER",
           "events": [
             {"introduced": "7.7"},
             {"fixed": "7.78.0"}
           ]
        },
        {
           "type": "GIT",
           "repo": "https://github.com/curl/curl.git",
           "events": [
             {"introduced": "a1d6ad26100bc493c7b04f1301b1634b7f5aa8b4"},
             {"fixed": "894f6ec730597eb243618d33cc84d71add8d6a8a"}
           ]
        }
      ],
      "versions": [
        "7.77.0", "7.76.1", "7.76.0", "7.75.0", "7.74.0", "7.73.0", "7.72.0", 
        "7.71.1", "7.71.0", "7.70.0", "7.69.1", "7.69.0", "7.68.0", "7.67.0", 
        "7.66.0", "7.65.3", "7.65.2", "7.65.1", "7.65.0", "7.64.1", "7.64.0", 
        "7.63.0", "7.62.0", "7.61.1", "7.61.0", "7.60.0", "7.59.0", "7.58.0", 
        "7.57.0", "7.56.1", "7.56.0", "7.55.1", "7.55.0", "7.54.1", "7.54.0", 
        "7.53.1", "7.53.0", "7.52.1", "7.52.0", "7.51.0", "7.50.3", "7.50.2", 
        "7.50.1", "7.50.0", "7.49.1", "7.49.0", "7.48.0", "7.47.1", "7.47.0", 
        "7.46.0", "7.45.0", "7.44.0", "7.43.0", "7.42.1", "7.42.0", "7.41.0", 
        "7.40.0", "7.39.0", "7.38.0", "7.37.1", "7.37.0", "7.36.0", "7.35.0", 
        "7.34.0", "7.33.0", "7.32.0", "7.31.0", "7.30.0", "7.29.0", "7.28.1", 
        "7.28.0", "7.27.0", "7.26.0", "7.25.0", "7.24.0", "7.23.1", "7.23.0", 
        "7.22.0", "7.21.7", "7.21.6", "7.21.5", "7.21.4", "7.21.3", "7.21.2", 
        "7.21.1", "7.21.0", "7.20.1", "7.20.0", "7.19.7", "7.19.6", "7.19.5", 
        "7.19.4", "7.19.3", "7.19.2", "7.19.1", "7.19.0", "7.18.2", "7.18.1", 
        "7.18.0", "7.17.1", "7.17.0", "7.16.4", "7.16.3", "7.16.2", "7.16.1", 
        "7.16.0", "7.15.5", "7.15.4", "7.15.3", "7.15.2", "7.15.1", "7.15.0", 
        "7.14.1", "7.14.0", "7.13.2", "7.13.1", "7.13.0", "7.12.3", "7.12.2", 
        "7.12.1", "7.12.0", "7.11.2", "7.11.1", "7.11.0", "7.10.8", "7.10.7", 
        "7.10.6", "7.10.5", "7.10.4", "7.10.3", "7.10.2", "7.10.1", "7.10", 
        "7.9.8", "7.9.7", "7.9.6", "7.9.5", "7.9.4", "7.9.3", "7.9.2", 
        "7.9.1", "7.9", "7.8.1", "7.8", "7.7.3", "7.7.2", "7.7.1", 
        "7.7"
      ]
    }
  ],
  "credits": [
    {
      "name": "Red Hat Product Security",
      "type": "FINDER"
    },
    {
      "name": "Red Hat Product Security",
      "type": "REMEDIATION_DEVELOPER"
    }
  ],
  "details": "curl supports the `-t` command line option, known as `CURLOPT_TELNETOPTIONS`\nin libcurl. This rarely used option is used to send variable=content pairs to\nTELNET servers.\n\nDue to flaw in the option parser for sending `NEW_ENV` variables, libcurl\ncould be made to pass on uninitialized data from a stack based buffer to the\nserver. Therefore potentially revealing sensitive internal information to the\nserver using a clear-text network protocol.\n\nThis could happen because curl did not call and use `sscanf()` correctly when\nparsing the string provided by the application.\n\nThe previous curl security vulnerability\n[CVE-2021-22898](https://curl.se/docs/CVE-2021-22898.html) is almost identical\nto this one but the fix was insufficient so this security vulnerability\nremained."
}