{
  "cveId": "CVE-2019-18840",
  "url": "https://patchblox.com/security/cve/CVE-2019-18840",
  "summary": "CVE-2019-18840 is fixed in libwolfssl23 on 1 platform by libwolfssl23 4.2.0\u002Bdfsg-3 (version 4.2.0\u002Bdfsg-3), released November 9, 2019. It is not reported as exploited. Patch Radar priority: Routine.",
  "title": "libwolfssl23: In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data...",
  "description": "In wolfSSL 4.1.0 through 4.2.0c, there are missing sanity checks of memory accesses in parsing ASN.1 certificate data while handshaking. Specifically, there is a one-byte heap-based buffer overflow inside the DecodedCert structure in GetName in wolfcrypt/src/asn.c because the domain name location index is mishandled. Because a pointer is overwritten, there is an invalid free.",
  "published": "2019-11-09T05:15:00Z",
  "severity": "Medium",
  "epss": 0.01972,
  "epssPercentile": 0.80543,
  "priority": "Routine",
  "priorityTier": 4,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "libwolfssl23",
      "release": "Ubuntu 20.04 LTS (focal)",
      "fixedVersion": "4.2.0\u002Bdfsg-3",
      "fix": "libwolfssl23 4.2.0\u002Bdfsg-3",
      "url": "https://patchblox.com/security/fix/linux/ubuntu-focal-libwolfssl23-4.2.0-dfsg-3",
      "released": "2019-11-09T05:15:00Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T00:53:09Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}