CVE-2024-53981: Python multipart Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-59g5-xgcq-4qw3
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CVSS 7.5
CWE-770
Published
Advisory Summary

CVE-2024-53981 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-770: Allocation of Resources Without Limits or Throttling) affecting Python multipart libraries in the PyPI ecosystem. The issue involves denial of service (dos) via deformation `multipart/form-data` boundary. Remediation is available by upgrading affected packages to version 0.0.18.

CVE-2024-53981 at a Glance

CVE Identifier CVE-2024-53981
GHSA Identifier GHSA-59g5-xgcq-4qw3
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-770: Allocation of Resources Without Limits or Throttling
Affected Product Python multipart
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-2024-53981

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

python-multipart fixed: 0.0.18 
pip install python-multipart>=0.0.18
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 python-multipart

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2024-53981, inspect your installed packages using pip:

pip show python-multipart

Analyze the terminal output to locate any version of Python multipart in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.0.18), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-770: Allocation of Resources Without Limits or Throttling, where the product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. In Python multipart, 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

### Summary When parsing form data, `python-multipart` skips line breaks (CR `\r` or LF `\n`) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs. An attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS). ### Impact Applications that use `python-multipart` to parse form data (or use frameworks that do so) are affected. ### Original Report This security issue was reported by: - GitHub security advisory in Starlette on October 30 by @Startr4ck - Email to `python-multipart` maintainer on October 3 by @mnqazi

CVE-2024-53981 Affected Python multipart Versions

1 component(s)
Fixed Versions:
0.0.18
Product / Package Ecosystem Affected Versions Fixed Version
python-multipart
pypi/python-multipart
PyPI
< 0.0.18
0.0.18

References

GitHub Advisory / Wiki ADVISORY
https://github.com/Kludex/python-multipart/security/advisories/GHSA-59g5-xgcq-4qw3
NVD — CVE-2024-53981 NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-53981
Security Fix Commit FIX COMMIT
https://github.com/Kludex/python-multipart/commit/c4fe4d3cebc08c660e57dd709af1ffa7059b3177
Python multipart Source Repository REPOSITORY
https://github.com/Kludex/python-multipart

Frequently Asked Questions

What is CVE-2024-53981?
CVE-2024-53981 is a security vulnerability in Python multipart involving Denial of service (DoS) via deformation `multipart/form-data` boundary under CWE-770: Allocation of Resources Without Limits or Throttling.
Which Python multipart versions are affected?
Affected versions include releases prior to 0.0.18 across affected packages: python-multipart.
What version fixes CVE-2024-53981?
Upgrading to 0.0.18 (or the latest patched release for your respective branch) resolves the vulnerability.
Is python-multipart affected?
Yes, python-multipart is affected in releases prior to 0.0.18. Upgrade your dependency to 0.0.18 or later.
What is the CVSS score of CVE-2024-53981?
CVE-2024-53981 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-2024-53981?
CVE-2024-53981 is classified under CWE-770: Allocation of Resources Without Limits or Throttling (The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.).
How can I check PyPI dependencies for CVE-2024-53981?
Run the dependency tree command: 'pip show python-multipart'. 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-59g5-xgcq-4qw3",
  "modified" : "2024-12-02T21:37:04Z",
  "published" : "2024-12-02T21:37:04Z",
  "aliases" : [ "CVE-2024-53981" ],
  "summary" : "Denial of service (DoS) via deformation `multipart/form-data` boundary",
  "details" : "### Summary\n\nWhen parsing form data, `python-multipart` skips line breaks (CR `\\r` or LF `\\n`) in front of the first boundary and any tailing bytes after the last boundary. This happens one byte at a time and emits a log event each time, which may cause excessive logging for certain inputs.\n\nAn attacker could abuse this by sending a malicious request with lots of data before the first or after the last boundary, causing high CPU load and stalling the processing thread for a significant amount of time. In case of ASGI application, this could stall the event loop and prevent other requests from being processed, resulting in a denial of service (DoS).\n\n### Impact\n\nApplications that use `python-multipart` to parse form data (or use frameworks that do so) are affected. \n\n### Original Report\n\nThis security issue was reported by:\n- GitHub security advisory in Starlette on October 30 by @Startr4ck\n- Email to `python-multipart` maintainer on October 3 by @mnqazi",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
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      "ecosystem" : "PyPI",
      "name" : "python-multipart"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
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      } ]
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  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/Kludex/python-multipart/security/advisories/GHSA-59g5-xgcq-4qw3"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2024-53981"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/Kludex/python-multipart/commit/c4fe4d3cebc08c660e57dd709af1ffa7059b3177"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/Kludex/python-multipart"
  } ],
  "database_specific" : {
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    "severity" : "HIGH",
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    "github_reviewed_at" : "2024-12-02T21:37:04Z",
    "nvd_published_at" : "2024-12-02T16:15:14Z"
  }
}