Vulnerability-Lookup

OPENSUSE-SU-2026:20015-1

Vulnerability from csaf_opensuse - Published: 2026-01-12 10:29 - Updated: 2026-01-12 10:29

Summary

Security update for python-tornado6

Notes

Title of the patch

Security update for python-tornado6

Description of the patch

This update for python-tornado6 fixes the following issues: - CVE-2025-67724: unescaped `reason` argument used in HTTP headers and in HTML default error pages can be used by attackers to launch header injection or XSS attacks (bsc#1254903). - CVE-2025-67725: quadratic complexity of string concatenation operations used by the `HTTPHeaders.add` method can lead o DoS when processing a maliciously crafted HTTP request (bsc#1254905). - CVE-2025-67726: quadratic complexity algorithm used in the `_parseparam` function of `httputil.py` can lead to DoS when processing maliciously crafted parameters in a `Content-Disposition` header (bsc#1254904).

Patchnames

openSUSE-Leap-16.0-129

CSAF 2.0 data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0).

JSON

To clipboard

{
  "document": {
    "aggregate_severity": {
      "namespace": "https://www.suse.com/support/security/rating/",
      "text": "important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Copyright 2024 SUSE LLC. All rights reserved.",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en",
    "notes": [
      {
        "category": "summary",
        "text": "Security update for python-tornado6",
        "title": "Title of the patch"
      },
      {
        "category": "description",
        "text": "This update for python-tornado6 fixes the following issues:\n\n- CVE-2025-67724: unescaped `reason` argument used in HTTP headers and in HTML default error pages can be used by\n  attackers to launch header injection or XSS attacks (bsc#1254903).\n- CVE-2025-67725: quadratic complexity of string concatenation operations used by the `HTTPHeaders.add` method can lead\n  o DoS when processing a maliciously crafted HTTP request (bsc#1254905).\n- CVE-2025-67726: quadratic complexity algorithm used in the `_parseparam` function of `httputil.py` can lead to DoS\n  when processing maliciously crafted parameters in a `Content-Disposition` header (bsc#1254904).\n",
        "title": "Description of the patch"
      },
      {
        "category": "details",
        "text": "openSUSE-Leap-16.0-129",
        "title": "Patchnames"
      },
      {
        "category": "legal_disclaimer",
        "text": "CSAF 2.0 data is provided by SUSE under the Creative Commons License 4.0 with Attribution (CC-BY-4.0).",
        "title": "Terms of use"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "https://www.suse.com/support/security/contact/",
      "name": "SUSE Product Security Team",
      "namespace": "https://www.suse.com/"
    },
    "references": [
      {
        "category": "external",
        "summary": "SUSE ratings",
        "url": "https://www.suse.com/support/security/rating/"
      },
      {
        "category": "self",
        "summary": "URL of this CSAF notice",
        "url": "https://ftp.suse.com/pub/projects/security/csaf/opensuse-su-2026_20015-1.json"
      },
      {
        "category": "self",
        "summary": "SUSE Bug 1254903",
        "url": "https://bugzilla.suse.com/1254903"
      },
      {
        "category": "self",
        "summary": "SUSE Bug 1254904",
        "url": "https://bugzilla.suse.com/1254904"
      },
      {
        "category": "self",
        "summary": "SUSE Bug 1254905",
        "url": "https://bugzilla.suse.com/1254905"
      },
      {
        "category": "self",
        "summary": "SUSE CVE CVE-2025-67724 page",
        "url": "https://www.suse.com/security/cve/CVE-2025-67724/"
      },
      {
        "category": "self",
        "summary": "SUSE CVE CVE-2025-67725 page",
        "url": "https://www.suse.com/security/cve/CVE-2025-67725/"
      },
      {
        "category": "self",
        "summary": "SUSE CVE CVE-2025-67726 page",
        "url": "https://www.suse.com/security/cve/CVE-2025-67726/"
      }
    ],
    "title": "Security update for python-tornado6",
    "tracking": {
      "current_release_date": "2026-01-12T10:29:37Z",
      "generator": {
        "date": "2026-01-12T10:29:37Z",
        "engine": {
          "name": "cve-database.git:bin/generate-csaf.pl",
          "version": "1"
        }
      },
      "id": "openSUSE-SU-2026:20015-1",
      "initial_release_date": "2026-01-12T10:29:37Z",
      "revision_history": [
        {
          "date": "2026-01-12T10:29:37Z",
          "number": "1",
          "summary": "Current version"
        }
      ],
      "status": "final",
      "version": "1"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "branches": [
              {
                "category": "product_version",
                "name": "python313-tornado6-6.5-160000.3.1.aarch64",
                "product": {
                  "name": "python313-tornado6-6.5-160000.3.1.aarch64",
                  "product_id": "python313-tornado6-6.5-160000.3.1.aarch64"
                }
              }
            ],
            "category": "architecture",
            "name": "aarch64"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "python313-tornado6-6.5-160000.3.1.ppc64le",
                "product": {
                  "name": "python313-tornado6-6.5-160000.3.1.ppc64le",
                  "product_id": "python313-tornado6-6.5-160000.3.1.ppc64le"
                }
              }
            ],
            "category": "architecture",
            "name": "ppc64le"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "python313-tornado6-6.5-160000.3.1.s390x",
                "product": {
                  "name": "python313-tornado6-6.5-160000.3.1.s390x",
                  "product_id": "python313-tornado6-6.5-160000.3.1.s390x"
                }
              }
            ],
            "category": "architecture",
            "name": "s390x"
          },
          {
            "branches": [
              {
                "category": "product_version",
                "name": "python313-tornado6-6.5-160000.3.1.x86_64",
                "product": {
                  "name": "python313-tornado6-6.5-160000.3.1.x86_64",
                  "product_id": "python313-tornado6-6.5-160000.3.1.x86_64"
                }
              }
            ],
            "category": "architecture",
            "name": "x86_64"
          },
          {
            "branches": [
              {
                "category": "product_name",
                "name": "openSUSE Leap 16.0",
                "product": {
                  "name": "openSUSE Leap 16.0",
                  "product_id": "openSUSE Leap 16.0"
                }
              }
            ],
            "category": "product_family",
            "name": "SUSE Linux Enterprise"
          }
        ],
        "category": "vendor",
        "name": "SUSE"
      }
    ],
    "relationships": [
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "python313-tornado6-6.5-160000.3.1.aarch64 as component of openSUSE Leap 16.0",
          "product_id": "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64"
        },
        "product_reference": "python313-tornado6-6.5-160000.3.1.aarch64",
        "relates_to_product_reference": "openSUSE Leap 16.0"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "python313-tornado6-6.5-160000.3.1.ppc64le as component of openSUSE Leap 16.0",
          "product_id": "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le"
        },
        "product_reference": "python313-tornado6-6.5-160000.3.1.ppc64le",
        "relates_to_product_reference": "openSUSE Leap 16.0"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "python313-tornado6-6.5-160000.3.1.s390x as component of openSUSE Leap 16.0",
          "product_id": "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x"
        },
        "product_reference": "python313-tornado6-6.5-160000.3.1.s390x",
        "relates_to_product_reference": "openSUSE Leap 16.0"
      },
      {
        "category": "default_component_of",
        "full_product_name": {
          "name": "python313-tornado6-6.5-160000.3.1.x86_64 as component of openSUSE Leap 16.0",
          "product_id": "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
        },
        "product_reference": "python313-tornado6-6.5-160000.3.1.x86_64",
        "relates_to_product_reference": "openSUSE Leap 16.0"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2025-67724",
      "ids": [
        {
          "system_name": "SUSE CVE Page",
          "text": "https://www.suse.com/security/cve/CVE-2025-67724"
        }
      ],
      "notes": [
        {
          "category": "general",
          "text": "Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom \"reason\" phrases (the \"Not Found\" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes). This issue is fixed in version 6.5.3.",
          "title": "CVE description"
        }
      ],
      "product_status": {
        "recommended": [
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
        ]
      },
      "references": [
        {
          "category": "external",
          "summary": "CVE-2025-67724",
          "url": "https://www.suse.com/security/cve/CVE-2025-67724"
        },
        {
          "category": "external",
          "summary": "SUSE Bug 1254903 for CVE-2025-67724",
          "url": "https://bugzilla.suse.com/1254903"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or \"zypper patch\".\n",
          "product_ids": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
            "version": "3.1"
          },
          "products": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "date": "2026-01-12T10:29:37Z",
          "details": "moderate"
        }
      ],
      "title": "CVE-2025-67724"
    },
    {
      "cve": "CVE-2025-67725",
      "ids": [
        {
          "system_name": "SUSE CVE Page",
          "text": "https://www.suse.com/security/cve/CVE-2025-67725"
        }
      ],
      "notes": [
        {
          "category": "general",
          "text": "Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server\u0027s event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS).  Due to Python string immutability, each concatenation copies the entire string, resulting in O(n^2) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3.",
          "title": "CVE description"
        }
      ],
      "product_status": {
        "recommended": [
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
        ]
      },
      "references": [
        {
          "category": "external",
          "summary": "CVE-2025-67725",
          "url": "https://www.suse.com/security/cve/CVE-2025-67725"
        },
        {
          "category": "external",
          "summary": "SUSE Bug 1254905 for CVE-2025-67725",
          "url": "https://bugzilla.suse.com/1254905"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or \"zypper patch\".\n",
          "product_ids": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "date": "2026-01-12T10:29:37Z",
          "details": "important"
        }
      ],
      "title": "CVE-2025-67725"
    },
    {
      "cve": "CVE-2025-67726",
      "ids": [
        {
          "system_name": "SUSE CVE Page",
          "text": "https://www.suse.com/security/cve/CVE-2025-67726"
        }
      ],
      "notes": [
        {
          "category": "general",
          "text": "Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server\u0027s CPU usage increases quadratically (O(n^2)) during parsing. Due to Tornado\u0027s single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3.",
          "title": "CVE description"
        }
      ],
      "product_status": {
        "recommended": [
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
          "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
        ]
      },
      "references": [
        {
          "category": "external",
          "summary": "CVE-2025-67726",
          "url": "https://www.suse.com/security/cve/CVE-2025-67726"
        },
        {
          "category": "external",
          "summary": "SUSE Bug 1254904 for CVE-2025-67726",
          "url": "https://bugzilla.suse.com/1254904"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "details": "To install this SUSE Security Update use the SUSE recommended installation methods like YaST online_update or \"zypper patch\".\n",
          "product_ids": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          },
          "products": [
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.aarch64",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.ppc64le",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.s390x",
            "openSUSE Leap 16.0:python313-tornado6-6.5-160000.3.1.x86_64"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "date": "2026-01-12T10:29:37Z",
          "details": "important"
        }
      ],
      "title": "CVE-2025-67726"
    }
  ]
}

CVE-2025-67725 (GCVE-0-2025-67725)

Vulnerability from cvelistv5 – Published: 2025-12-12 05:49 – Updated: 2025-12-18 18:51

Title

Tornado is Vulnerable to Quadratic DoS via Repeated Header Coalescing

Summary

Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server's event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS). Due to Python string immutability, each concatenation copies the entire string, resulting in O(n²) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3.

Severity ?

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M

References

URL

Tags

	https://github.com/tornadoweb/tornado/security/ad…	x_refsource_CONFIRM
	https://github.com/tornadoweb/tornado/commit/7714…	x_refsource_MISC
	https://github.com/tornadoweb/tornado/releases/ta…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	tornadoweb	tornado	Affected: < 6.5.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-67725",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-18T18:50:52.619221Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-12-18T18:51:00.369Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "tornado",
          "vendor": "tornadoweb",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.5.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, a single maliciously crafted HTTP request can block the server\u0027s event loop for an extended period, caused by the HTTPHeaders.add method. The function accumulates values using string concatenation when the same header name is repeated, causing a Denial of Service (DoS).  Due to Python string immutability, each concatenation copies the entire string, resulting in O(n\u00b2) time complexity. The severity can vary from high if max_header_size has been increased from its default, to low if it has its default value of 64KB. This issue is fixed in version 6.5.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-12T05:49:41.523Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-c98p-7wgm-6p64",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-c98p-7wgm-6p64"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3"
        }
      ],
      "source": {
        "advisory": "GHSA-c98p-7wgm-6p64",
        "discovery": "UNKNOWN"
      },
      "title": "Tornado is Vulnerable to Quadratic DoS via Repeated Header Coalescing"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-67725",
    "datePublished": "2025-12-12T05:49:41.523Z",
    "dateReserved": "2025-12-10T19:25:20.819Z",
    "dateUpdated": "2025-12-18T18:51:00.369Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2025-67724 (GCVE-0-2025-67724)

Vulnerability from cvelistv5 – Published: 2025-12-12 05:36 – Updated: 2025-12-18 18:53

Title

Tornado vulnerable to Header Injection and XSS via reason argument

Summary

Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom "reason" phrases (the "Not Found" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes). This issue is fixed in version 6.5.3.

Severity ?

5.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
CWE-644 - Improper Neutralization of HTTP Headers for Scripting Syntax

Assigner

GitHub_M

References

URL

Tags

	https://github.com/tornadoweb/tornado/security/ad…	x_refsource_CONFIRM
	https://github.com/tornadoweb/tornado/commit/9c16…	x_refsource_MISC
	https://github.com/tornadoweb/tornado/releases/ta…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	tornadoweb	tornado	Affected: < 6.5.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-67724",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-18T18:53:21.062311Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-12-18T18:53:38.061Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "tornado",
          "vendor": "tornadoweb",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.5.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Tornado is a Python web framework and asynchronous networking library. In versions 6.5.2 and below, the supplied reason phrase is used unescaped in HTTP headers (where it could be used for header injection) or in HTML in the default error page (where it could be used for XSS) and can be exploited by passing untrusted or malicious data into the reason argument. Used by both RequestHandler.set_status and tornado.web.HTTPError, the argument is designed to allow applications to pass custom \"reason\" phrases (the \"Not Found\" in HTTP/1.1 404 Not Found) to the HTTP status line (mainly for non-standard status codes). This issue is fixed in version 6.5.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.4,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-644",
              "description": "CWE-644: Improper Neutralization of HTTP Headers for Scripting Syntax",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-12T05:36:59.992Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-pr2v-jx2c-wg9f",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-pr2v-jx2c-wg9f"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/commit/9c163aebeaad9e6e7d28bac1f33580eb00b0e421",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/commit/9c163aebeaad9e6e7d28bac1f33580eb00b0e421"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3"
        }
      ],
      "source": {
        "advisory": "GHSA-pr2v-jx2c-wg9f",
        "discovery": "UNKNOWN"
      },
      "title": "Tornado vulnerable to Header Injection and XSS via reason argument"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-67724",
    "datePublished": "2025-12-12T05:36:59.992Z",
    "dateReserved": "2025-12-10T19:25:20.819Z",
    "dateUpdated": "2025-12-18T18:53:38.061Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

CVE-2025-67726 (GCVE-0-2025-67726)

Vulnerability from cvelistv5 – Published: 2025-12-12 06:13 – Updated: 2025-12-18 18:48

Title

Tornado is Vulnerable to Quadratic DoS via Crafted Multipart Parameters

Summary

Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server's CPU usage increases quadratically (O(n²)) during parsing. Due to Tornado's single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3.

Severity ?

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-834 - Excessive Iteration
CWE-400 - Uncontrolled Resource Consumption

Assigner

GitHub_M

References

URL

Tags

	https://github.com/tornadoweb/tornado/security/ad…	x_refsource_CONFIRM
	https://github.com/tornadoweb/tornado/commit/7714…	x_refsource_MISC
	https://github.com/tornadoweb/tornado/releases/ta…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	tornadoweb	tornado	Affected: < 6.5.3

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-67726",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-12-18T18:47:53.473225Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-12-18T18:48:49.007Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "tornado",
          "vendor": "tornadoweb",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.5.3"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Tornado is a Python web framework and asynchronous networking library. Versions 6.5.2 and below use an inefficient algorithm when parsing parameters for HTTP header values, potentially causing a DoS. The _parseparam function in httputil.py is used to parse specific HTTP header values, such as those in multipart/form-data and repeatedly calls string.count() within a nested loop while processing quoted semicolons. If an attacker sends a request with a large number of maliciously crafted parameters in a Content-Disposition header, the server\u0027s CPU usage increases quadratically (O(n\u00b2)) during parsing. Due to Tornado\u0027s single event loop architecture, a single malicious request can cause the entire server to become unresponsive for an extended period. This issue is fixed in version 6.5.3."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-834",
              "description": "CWE-834: Excessive Iteration",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-400",
              "description": "CWE-400: Uncontrolled Resource Consumption",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-12-12T06:13:51.336Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-jhmp-mqwm-3gq8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/tornadoweb/tornado/security/advisories/GHSA-jhmp-mqwm-3gq8"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/commit/771472cfdaeebc0d89a9cc46e249f8891a6b29cd"
        },
        {
          "name": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/tornadoweb/tornado/releases/tag/v6.5.3"
        }
      ],
      "source": {
        "advisory": "GHSA-jhmp-mqwm-3gq8",
        "discovery": "UNKNOWN"
      },
      "title": "Tornado is Vulnerable to Quadratic DoS via Crafted Multipart Parameters"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-67726",
    "datePublished": "2025-12-12T06:13:51.336Z",
    "dateReserved": "2025-12-10T19:25:20.819Z",
    "dateUpdated": "2025-12-18T18:48:49.007Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Tags

Taxonomy of the tags.

All sightings related to this event Export sightings related to this event

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

OPENSUSE-SU-2026:20015-1

CVE-2025-67725 (GCVE-0-2025-67725)

CVE-2025-67724 (GCVE-0-2025-67724)

CVE-2025-67726 (GCVE-0-2025-67726)

Tags

Sightings

Nomenclature