{
  "cveId": "CVE-2021-22890",
  "url": "https://patchblox.com/security/cve/CVE-2021-22890",
  "summary": "CVE-2021-22890 is fixed in 4 products on 1 platform, first by curl 7.68.0-1ubuntu2.5, released March 30, 2021. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "curl: curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection d...",
  "description": "curl 7.63.0 to and including 7.75.0 includes vulnerability that allows a malicious HTTPS proxy to MITM a connection due to bad handling of TLS 1.3 session tickets. When using a HTTPS proxy and TLS 1.3, libcurl can confuse session tickets arriving from the HTTPS proxy but work as if they arrived from the remote server and then wrongly \u0022short-cut\u0022 the host handshake. When confusing the tickets, a HTTPS proxy can trick libcurl to use the wrong session ticket resume for the host and thereby circumvent the server TLS certificate check and make a MITM attack to be possible to perform unnoticed. Note that such a malicious HTTPS proxy needs to provide a certificate that curl will accept for the MITMed server for an attack to work - unless curl has been told to ignore the server certificate check.",
  "published": "2021-03-30T23:00:00Z",
  "severity": "Medium",
  "epss": 0.03057,
  "epssPercentile": 0.8768,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "curl",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "7.68.0-1ubuntu2.5",
      "fix": "curl 7.68.0-1ubuntu2.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-curl-7.68.0-1ubuntu2.5",
      "released": "2021-03-30T23:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libcurl3-gnutls",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "7.68.0-1ubuntu2.5",
      "fix": "libcurl3-gnutls 7.68.0-1ubuntu2.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libcurl3-gnutls-7.68.0-1ubuntu2.5",
      "released": "2021-03-30T23:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libcurl3-nss",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "7.68.0-1ubuntu2.5",
      "fix": "libcurl3-nss 7.68.0-1ubuntu2.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libcurl3-nss-7.68.0-1ubuntu2.5",
      "released": "2021-03-30T23:00:00Z"
    },
    {
      "platform": "linux",
      "product": "libcurl4",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "7.68.0-1ubuntu2.5",
      "fix": "libcurl4 7.68.0-1ubuntu2.5",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libcurl4-7.68.0-1ubuntu2.5",
      "released": "2021-03-30T23:00:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-09T07:25:28Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}