{
  "id": "CVE-2018-6789",
  "url": "https://spydr.io/cve/CVE-2018-6789",
  "published": "2018-02-08T23:29:01.170Z",
  "modified": "2026-06-17T02:02:17.180Z",
  "score": 9.8,
  "severity": "critical",
  "cvss_version": "3.1",
  "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
  "score_source": "NVD",
  "epss": 0.82137,
  "epss_percentile": 0.99649,
  "exploited": true,
  "kev": {
    "added": "2021-11-03",
    "due": "2022-05-03",
    "action": "Apply updates per vendor instructions.",
    "ransomware": "Known",
    "name": "Exim Buffer Overflow Vulnerability",
    "notes": "https://nvd.nist.gov/vuln/detail/CVE-2018-6789"
  },
  "ssvc_exploitation": "active",
  "vendors": [
    "exim",
    "debian",
    "canonical"
  ],
  "products": [
    "exim",
    "debian linux",
    "canonical ubuntu linux"
  ],
  "cwes": [
    "CWE-120"
  ],
  "description": "An issue was discovered in the base64d function in the SMTP listener in Exim before 4.90.1. By sending a handcrafted message, a buffer overflow may happen. This can be used to execute code remotely.",
  "status": "Analyzed",
  "score_type": "Primary",
  "scores": {
    "cvss_v40": null,
    "cvss_v31": 9.8,
    "cvss_v30": null
  },
  "references": [
    {
      "url": "http://openwall.com/lists/oss-security/2018/02/10/2",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ]
    },
    {
      "url": "http://packetstormsecurity.com/files/162959/Exim-base64d-Buffer-Overflow.html",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://www.openwall.com/lists/oss-security/2018/02/07/2",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ]
    },
    {
      "url": "http://www.securityfocus.com/bid/103049",
      "tags": [
        "Broken Link",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "http://www.securitytracker.com/id/1040461",
      "tags": [
        "Broken Link",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://devco.re/blog/2018/03/06/exim-off-by-one-RCE-exploiting-CVE-2018-6789-en/",
      "tags": [
        "Exploit",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://exim.org/static/doc/security/CVE-2018-6789.txt",
      "tags": [
        "Vendor Advisory"
      ]
    },
    {
      "url": "https://git.exim.org/exim.git/commit/cf3cd306062a08969c41a1cdd32c6855f1abecf1",
      "tags": [
        "Patch"
      ]
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2018/02/msg00009.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://usn.ubuntu.com/3565-1/",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.debian.org/security/2018/dsa-4110",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://www.exploit-db.com/exploits/44571/",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://www.exploit-db.com/exploits/45671/",
      "tags": [
        "Exploit",
        "Third Party Advisory",
        "VDB Entry"
      ]
    },
    {
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-6789",
      "tags": [
        "US Government Resource"
      ]
    }
  ],
  "nvd_url": "https://nvd.nist.gov/vuln/detail/CVE-2018-6789",
  "covered_in": [],
  "attribution": [
    {
      "source": "NVD",
      "url": "https://nvd.nist.gov",
      "notice": "This product uses data from the NVD API but is not endorsed or certified by the NVD."
    },
    {
      "source": "CISA KEV",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "notice": "Known exploited vulnerabilities from the CISA KEV catalog."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss",
      "notice": "Exploit prediction scores from FIRST EPSS."
    }
  ]
}