CVE-2023-25577: Werkzeug Remote Code Execution Vulnerability

HIGH
Advisory Identifier: GHSA-xg9f-g7g7-2323
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CVSS 7.5
CWE-400 CWE-770
Published
Advisory Summary

CVE-2023-25577 is a HIGH (CVSS 7.5) remote code execution vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Werkzeug libraries in the PyPI ecosystem. The issue involves high resource usage when parsing multipart form data with many fields. Remediation is available by upgrading affected packages to version 2.2.3.

CVE-2023-25577 at a Glance

CVE Identifier CVE-2023-25577
GHSA Identifier GHSA-xg9f-g7g7-2323
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Werkzeug
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-2023-25577

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

Werkzeug fixed: 2.2.3 
pip install Werkzeug>=2.2.3
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 Werkzeug

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-25577, inspect your installed packages using pip:

pip show Werkzeug

Analyze the terminal output to locate any version of Werkzeug in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.2.3), your application is affected.

Note: The pip show Werkzeug 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 Werkzeug, 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

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.

CVE-2023-25577 Affected Werkzeug Versions

1 component(s)
Fixed Versions:
2.2.3
Product / Package Ecosystem Affected Versions Fixed Version
Werkzeug
pypi/Werkzeug
PyPI
< 2.2.3
2.2.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/pallets/werkzeug/security/advisories/GHSA-xg9f-g7g7-2323
Werkzeug Source Repository REPOSITORY
https://github.com/pallets/werkzeug
NVD — CVE-2023-25577 NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-25577
Security Fix Commit FIX COMMIT
https://github.com/pallets/werkzeug/commit/517cac5a804e8c4dc4ed038bb20dacd038e7a9f1
Werkzeug Release RELEASE
https://github.com/pallets/werkzeug/releases/tag/2.2.3
Werkzeug Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/werkzeug/PYSEC-2023-58.yaml
Werkzeug Security Information SECURITY
https://security.netapp.com/advisory/ntap-20230818-0003
Werkzeug Security Information SECURITY
https://www.debian.org/security/2023/dsa-5470

Frequently Asked Questions

What is CVE-2023-25577?
CVE-2023-25577 is a security vulnerability in Werkzeug involving High resource usage when parsing multipart form data with many fields under CWE-400: Uncontrolled Resource Consumption.
Which Werkzeug versions are affected?
Affected versions include releases prior to 2.2.3 across affected packages: Werkzeug.
What version fixes CVE-2023-25577?
Upgrading to 2.2.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Werkzeug affected?
Yes, Werkzeug is affected in releases prior to 2.2.3. Upgrade your dependency to 2.2.3 or later.
What is the CVSS score of CVE-2023-25577?
CVE-2023-25577 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-2023-25577?
CVE-2023-25577 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-2023-25577?
Run the dependency tree command: 'pip show Werkzeug'. 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-xg9f-g7g7-2323",
  "modified" : "2024-11-19T19:07:37Z",
  "published" : "2023-02-15T15:36:26Z",
  "aliases" : [ "CVE-2023-25577" ],
  "summary" : "High resource usage when parsing multipart form data with many fields",
  "details" : "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.\n\nThis 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.",
  "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" : "Werkzeug"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.2.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/pallets/werkzeug/security/advisories/GHSA-xg9f-g7g7-2323"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-25577"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pallets/werkzeug/commit/517cac5a804e8c4dc4ed038bb20dacd038e7a9f1"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/pallets/werkzeug"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pallets/werkzeug/releases/tag/2.2.3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/werkzeug/PYSEC-2023-58.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20230818-0003"
  }, {
    "type" : "WEB",
    "url" : "https://www.debian.org/security/2023/dsa-5470"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-770" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-02-15T15:36:26Z",
    "nvd_published_at" : "2023-02-14T20:15:00Z"
  }
}