{
  "cveId": "CVE-2021-3657",
  "url": "https://patchblox.com/security/cve/CVE-2021-3657",
  "summary": "CVE-2021-3657 is fixed in isync on 1 platform, first by DEBIAN-CVE-2021-3657, released February 18, 2022. It is not reported as exploited. Patch Radar priority: Urgent.",
  "title": "isync: A flaw was found in mbsync versions prior to 1.4.4",
  "description": "A flaw was found in mbsync versions prior to 1.4.4. Due to inadequate handling of extremely large (\u003E=2GiB) IMAP literals, malicious or compromised IMAP servers, and hypothetically even external email senders, could cause several different buffer overflows, which could conceivably be exploited for remote code execution.",
  "published": "2022-02-18T18:15:09Z",
  "severity": "critical",
  "cvss": 9.8,
  "cvssVector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "epss": 0.03488,
  "epssPercentile": 0.89207,
  "priority": "Urgent",
  "priorityTier": 2,
  "exploited": false,
  "vendorExploited": false,
  "disclosed": false,
  "fixes": [
    {
      "platform": "linux",
      "product": "isync",
      "release": "Debian 12.15 (bookworm)",
      "fixedVersion": "1.4.4-1",
      "fix": "DEBIAN-CVE-2021-3657",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-3657",
      "released": "2022-02-18T18:15:09Z"
    },
    {
      "platform": "linux",
      "product": "isync",
      "release": "Debian 13.5 (trixie)",
      "fixedVersion": "1.4.4-1",
      "fix": "DEBIAN-CVE-2021-3657",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-3657",
      "released": "2022-02-18T18:15:09Z"
    },
    {
      "platform": "linux",
      "product": "isync",
      "release": "Debian 14",
      "fixedVersion": "1.4.4-1",
      "fix": "DEBIAN-CVE-2021-3657",
      "url": "https://patchblox.com/security/fix/linux/debian-cve-2021-3657",
      "released": "2022-02-18T18:15:09Z"
    }
  ],
  "noFixYet": [],
  "dataAsOf": "2026-11-08T13:06:02Z",
  "attribution": {
    "text": "Data: Patchblox Patch Radar",
    "url": "https://patchblox.com/security/patch-radar",
    "terms": "https://patchblox.com/security/patch-radar/use-the-data"
  }
}