# CVE-2023-25577: High resource usage when parsing multipart form data with many fields

Source: https://junglewise.ai/threats/cve-2023-25577-high-resource-usage-when-parsing-multipart-form-data-with-many  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2023-02-14  
License: CC BY 4.0 with a link back

CVE-2023-25577 · Severity: low · CVSS 3.1 · Published 2023-02-14

Werkzeug is a comprehensive WSGI web application library. Prior to version 2.2.3, Werkzeug's multipart form data parser will parse an unlimited number of parts, including file parts. Parts can be a small amount of bytes, but each requires CPU time to parse and may use more memory as Python data. If a request can be made to an endpoint that accesses `request.data`, `request.form`, `request.files`, or `request.get_data(parse_form_data=False)`, it can cause unexpectedly high resource usage. This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. The amount of RAM required can trigger an out of memory kill of the process. Unlimited file parts can use up memory and file handles. If many concurrent requests are sent continuously, this can exhaust or kill all available workers. Version 2.2.3 contains a patch for this issue.

Technologies: [werkzeug (PyPI)](https://junglewise.ai/threats/technologies/werkzeug). Vendors: [PyPI](https://junglewise.ai/threats/vendors/pypi).

## Quick answers

**Is CVE-2023-25577 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2023-25577 being exploited in the wild.

**How severe is CVE-2023-25577?** Low severity, with a CVSS score of 3.1, published 14 February 2023.

**Which products and versions are affected?** werkzeug (PyPI) ECOSYSTEM:introduced=0,fixed=2.2.3, GIT:introduced=0,fixed=517cac5a804e8c4dc4ed038bb20dacd038e7a9f1|ECOSYSTEM:introduced=0,fixed=2.2.3.

**Is there a fix for CVE-2023-25577?** Yes. werkzeug (PyPI): upgrade to 2.2.3 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**Am I affected by CVE-2023-25577?** Check whether you run werkzeug (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- werkzeug (PyPI): upgrade to 2.2.3 or later

  ```sh
  pip install "werkzeug>=2.2.3"
  ```


## Affected products

- werkzeug (PyPI) ECOSYSTEM:introduced=0,fixed=2.2.3, GIT:introduced=0,fixed=517cac5a804e8c4dc4ed038bb20dacd038e7a9f1|ECOSYSTEM:introduced=0,fixed=2.2.3

## Identifiers

- CVE-2023-25577
- GHSA-xg9f-g7g7-2323
- PYSEC-2023-58

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