CVE-2024-52804: Tornado Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-8w49-h785-mj3c
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CVSS 7.5
CWE-400 CWE-770
Published
Advisory Summary

CVE-2024-52804 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Tornado libraries in the PyPI ecosystem. The issue involves tornado has an http cookie parsing dos vulnerability. Remediation is available by upgrading affected packages to version 6.4.2.

CVE-2024-52804 at a Glance

CVE Identifier CVE-2024-52804
GHSA Identifier GHSA-8w49-h785-mj3c
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Tornado
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 7.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2024-52804

To remediate this vulnerability, upgrade all affected Tornado dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

tornado fixed: 6.4.2 
pip install tornado>=6.4.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show tornado

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-52804, inspect your installed packages using pip:

pip show tornado

Analyze the terminal output to locate any version of Tornado in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.4.2), your application is affected.

Note: The pip show tornado command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Tornado, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing maliciously-crafted cookie headers. This parsing occurs in the event loop thread and may block the processing of other requests. See also CVE-2024-7592 for a similar vulnerability in cpython.

CVE-2024-52804 Affected Tornado Versions

1 component(s)
Fixed Versions:
6.4.2
Product / Package Ecosystem Affected Versions Fixed Version
tornado
pypi/tornado
PyPI
< 6.4.2
6.4.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/tornadoweb/tornado/security/advisories/GHSA-8w49-h785-mj3c
NVD — CVE-2024-52804 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-52804
Security Fix Commit FIX COMMIT
https://github.com/tornadoweb/tornado/commit/d5ba4a1695fbf7c6a3e54313262639b198291533
Tornado Source Repository REPOSITORY
https://github.com/tornadoweb/tornado
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2025/01/msg00000.html

Frequently Asked Questions

What is CVE-2024-52804?
CVE-2024-52804 is a security vulnerability in Tornado involving Tornado has an HTTP cookie parsing DoS vulnerability under CWE-400: Uncontrolled Resource Consumption.
Which Tornado versions are affected?
Affected versions include releases prior to 6.4.2 across affected packages: tornado.
What version fixes CVE-2024-52804?
Upgrading to 6.4.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is tornado affected?
Yes, tornado is affected in releases prior to 6.4.2. Upgrade your dependency to 6.4.2 or later.
What is the CVSS score of CVE-2024-52804?
CVE-2024-52804 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2024-52804?
CVE-2024-52804 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check PyPI dependencies for CVE-2024-52804?
Run the dependency tree command: 'pip show tornado'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8w49-h785-mj3c",
  "modified" : "2025-11-04T16:54:32Z",
  "published" : "2024-11-22T20:26:41Z",
  "aliases" : [ "CVE-2024-52804" ],
  "summary" : "Tornado has an HTTP cookie parsing DoS vulnerability",
  "details" : "The algorithm used for parsing HTTP cookies in Tornado versions prior to 6.4.2 sometimes has quadratic complexity, leading to excessive CPU consumption when parsing maliciously-crafted cookie headers. This parsing occurs in the event loop thread and may block the processing of other requests.\n\nSee also CVE-2024-7592 for a similar vulnerability in cpython.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "tornado"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "6.4.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.4.1"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/tornadoweb/tornado/security/advisories/GHSA-8w49-h785-mj3c"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-52804"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/tornadoweb/tornado/commit/d5ba4a1695fbf7c6a3e54313262639b198291533"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/tornadoweb/tornado"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2025/01/msg00000.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-11-22T20:26:41Z",
    "nvd_published_at" : "2024-11-22T16:15:34Z"
  }
}