ubuntu-cve-2025-47287
Vulnerability from osv_ubuntu
Published
2025-05-15 22:15
Modified
2026-04-27 14:25
Summary
Details

Tornado is a Python web framework and asynchronous networking library. When Tornado's multipart/form-data parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous. All versions of Tornado prior to 6.5.0 are affected. The vulnerable parser is enabled by default. Upgrade to Tornado version 6.50 to receive a patch. As a workaround, risk can be mitigated by blocking Content-Type: multipart/form-data in a proxy.

Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
N/A (UNKNOWN)
medium
References
To clipboard 

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-tornado",
            "binary_version": "4.2.1-1ubuntu3.1+esm3"
          },
          {
            "binary_name": "python3-tornado",
            "binary_version": "4.2.1-1ubuntu3.1+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:16.04:LTS",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@4.2.1-1ubuntu3.1+esm3?arch=source\u0026distro=esm-infra/xenial"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.2.1-1ubuntu2",
        "4.2.1-1ubuntu3",
        "4.2.1-1ubuntu3.1",
        "4.2.1-1ubuntu3.1+esm1",
        "4.2.1-1ubuntu3.1+esm2",
        "4.2.1-1ubuntu3.1+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python-tornado",
            "binary_version": "4.5.3-1ubuntu0.2+esm3"
          },
          {
            "binary_name": "python3-tornado",
            "binary_version": "4.5.3-1ubuntu0.2+esm3"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:18.04:LTS",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@4.5.3-1ubuntu0.2+esm3?arch=source\u0026distro=esm-apps/bionic"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "4.5.1-2.1~build2",
        "4.5.2-1",
        "4.5.3-1",
        "4.5.3-1ubuntu0.1",
        "4.5.3-1ubuntu0.2",
        "4.5.3-1ubuntu0.2+esm1",
        "4.5.3-1ubuntu0.2+esm2",
        "4.5.3-1ubuntu0.2+esm3"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "python3-tornado",
            "binary_version": "6.0.3+really5.1.1-3ubuntu0.1~esm5"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:20.04:LTS",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@6.0.3+really5.1.1-3ubuntu0.1~esm5?arch=source\u0026distro=esm-apps/focal"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "5.1.1-4ubuntu1",
        "5.1.1-4ubuntu5",
        "6.0.3+really5.1.1-2",
        "6.0.3+really5.1.1-2build1",
        "6.0.3+really5.1.1-2build2",
        "6.0.3+really5.1.1-3",
        "6.0.3+really5.1.1-3ubuntu0.1~esm1",
        "6.0.3+really5.1.1-3ubuntu0.1~esm3",
        "6.0.3+really5.1.1-3ubuntu0.1~esm5"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "Available with Ubuntu Pro: https://ubuntu.com/pro",
        "binaries": [
          {
            "binary_name": "python3-tornado",
            "binary_version": "6.1.0-3ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@6.1.0-3ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.0-3ubuntu0.1~esm2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.1.0-1build1",
        "6.1.0-2",
        "6.1.0-3",
        "6.1.0-3build1",
        "6.1.0-3ubuntu0.1~esm1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-tornado",
            "binary_version": "6.4.0-1ubuntu0.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@6.4.0-1ubuntu0.2?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.4.0-1ubuntu0.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.3.2-1",
        "6.4.0-0ubuntu1",
        "6.4.0-1",
        "6.4.0-1build1",
        "6.4.0-1ubuntu0.1"
      ]
    },
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-tornado",
            "binary_version": "6.4.2-2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "python-tornado",
        "purl": "pkg:deb/ubuntu/python-tornado@6.4.2-2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.4.2-2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "6.4.2-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Tornado is a Python web framework and asynchronous networking library. When Tornado\u0027s ``multipart/form-data`` parser encounters certain errors, it logs a warning but continues trying to parse the remainder of the data. This allows remote attackers to generate an extremely high volume of logs, constituting a DoS attack. This DoS is compounded by the fact that the logging subsystem is synchronous. All versions of Tornado prior to 6.5.0 are affected. The vulnerable parser is enabled by default. Upgrade to Tornado version 6.50 to receive a patch. As a workaround, risk can be mitigated by blocking `Content-Type: multipart/form-data` in a proxy.",
  "id": "UBUNTU-CVE-2025-47287",
  "modified": "2026-04-27T14:25:50Z",
  "published": "2025-05-15T22:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-47287"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-47287"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/tornadoweb/tornado/commit/b39b892bf78fe8fea01dd45199aa88307e7162f3"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-7cx3-6m66-7c5m"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-7547-1"
    }
  ],
  "related": [
    "USN-7547-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-47287"
  ]
}



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