CVE-2023-28837: Wagtail Wagtail Vulnerable To Denial-of-service Vulnerability

MODERATE
Advisory Identifier: GHSA-33pv-vcgh-jfg9
CVSS 4.4
CWE-400 CWE-770
Published
Advisory Summary

CVE-2023-28837 is a MODERATE (CVSS 4.4) wagtail vulnerable to denial-of-service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Wagtail libraries in the PyPI ecosystem. The issue involves wagtail vulnerable to denial-of-service via memory exhaustion when uploading large files. Remediation is available by upgrading affected packages to version 4.2.2, 4.1.4.

CVE-2023-28837 at a Glance

CVE Identifier CVE-2023-28837
GHSA Identifier GHSA-33pv-vcgh-jfg9
Severity MODERATE
CVSS v3.1 Base Score 4.4
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Wagtail
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 4.4

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

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required High (PR:H)
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-2023-28837

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

wagtail fixed: 4.2.2
pip install wagtail>=4.2.2
wagtail fixed: 4.1.4
pip install wagtail>=4.1.4
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 wagtail

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2023-28837, inspect your installed packages using pip:

pip show wagtail

Analyze the terminal output to locate any version of Wagtail in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 4.2.2), your application is affected.

Note: The pip show wagtail 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 Wagtail, 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

### Impact A memory exhaustion bug exists in Wagtail's handling of uploaded images and documents. For both images and documents, files are loaded into memory during upload for additional processing. A user with access to upload images or documents through the Wagtail admin interface could upload a file so large that it results in a crash or denial of service. The vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. It can only be exploited by admin users with permission to upload images or documents. Image uploads are [restricted to 10MB by default](https://docs.wagtail.org/en/stable/reference/settings.html#wagtailimages-max-upload-size), however this validation only happens on the frontend and on the backend after the vulnerable code. ### Patches Patched versions have been released as Wagtail 4.1.4 (for the LTS 4.1 branch) and Wagtail 4.2.2 (for the current 4.2 branch). ### Workarounds Site owners who are unable to upgrade to the new versions are encouraged to add extra protections outside of Wagtail to limit the size of uploaded files. Exactly how this is done will vary based on your hosting environment, but here are a few references for common setups: - Nginx: [`client_max_body_size`](https://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size) - Apache: [`LimitRequestBody`](https://httpd.apache.org/docs/2.4/mod/core.html#limitrequestbody) - Cloudflare: Already [imposes a limit of 100MB - 500MB](https://developers.cloudflare.com/cache/about/default-cache-behavior#customization-options-and-limitations) depending on plan - CloudFront: [`SizeConstraint`](https://docs.aws.amazon.com/waf/latest/APIReference/API_SizeConstraintStatement.html) - Traefik: [`traefik.http.middlewares.limit.buffering.maxRequestBodyBytes`](https://doc.traefik.io/traefik/middlewares/http/buffering/#maxrequestbodybytes) The changes themselves are deep inside Wagtail, making patching incredibly difficult.

CVE-2023-28837 Affected Wagtail Versions

2 component(s)
Fixed Versions:
4.2.24.1.4
Product / Package Ecosystem Affected Versions Fixed Version
wagtail
PyPI
≥ 4.2
< 4.2.2
4.2.2
wagtail
PyPI
< 4.1.4
4.1.4

References

Frequently Asked Questions

What is CVE-2023-28837?
CVE-2023-28837 is a security vulnerability in Wagtail involving Wagtail vulnerable to denial-of-service via memory exhaustion when uploading large files under CWE-400: Uncontrolled Resource Consumption.
Which Wagtail versions are affected?
Affected versions include releases prior to 4.2.2, 4.1.4 across affected packages: wagtail.
What version fixes CVE-2023-28837?
Upgrading to 4.2.2, 4.1.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is wagtail affected?
Yes, wagtail is affected in releases prior to 4.2.2, 4.1.4. Upgrade your dependency to 4.2.2, 4.1.4 or later.
What is the CVSS score of CVE-2023-28837?
CVE-2023-28837 has a CVSS v3.1 base score of 4.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2023-28837?
CVE-2023-28837 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-2023-28837?
Run the dependency tree command: 'pip show wagtail'. 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
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-33pv-vcgh-jfg9",
  "modified" : "2024-11-19T16:24:55Z",
  "published" : "2023-04-03T19:18:09Z",
  "aliases" : [ "CVE-2023-28837" ],
  "summary" : "Wagtail vulnerable to denial-of-service via memory exhaustion when uploading large files",
  "details" : "### Impact\n\nA memory exhaustion bug exists in Wagtail's handling of uploaded images and documents. For both images and documents, files are loaded into memory during upload for additional processing. A user with access to upload images or documents through the Wagtail admin interface could upload a file so large that it results in a crash or denial of service.\n\nThe vulnerability is not exploitable by an ordinary site visitor without access to the Wagtail admin. It can only be exploited by admin users with permission to upload images or documents.\n\nImage uploads are [restricted to 10MB by default](https://docs.wagtail.org/en/stable/reference/settings.html#wagtailimages-max-upload-size), however this validation only happens on the frontend and on the backend after the vulnerable code. \n\n### Patches\n\nPatched versions have been released as Wagtail 4.1.4 (for the LTS 4.1 branch) and Wagtail 4.2.2 (for the current 4.2 branch).\n\n### Workarounds\n\nSite owners who are unable to upgrade to the new versions are encouraged to add extra protections outside of Wagtail to limit the size of uploaded files. Exactly how this is done will vary based on your hosting environment, but here are a few references for common setups:\n\n- Nginx: [`client_max_body_size`](https://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size)\n- Apache: [`LimitRequestBody`](https://httpd.apache.org/docs/2.4/mod/core.html#limitrequestbody)\n- Cloudflare: Already [imposes a limit of 100MB - 500MB](https://developers.cloudflare.com/cache/about/default-cache-behavior#customization-options-and-limitations) depending on plan\n- CloudFront: [`SizeConstraint`](https://docs.aws.amazon.com/waf/latest/APIReference/API_SizeConstraintStatement.html)\n- Traefik: [`traefik.http.middlewares.limit.buffering.maxRequestBodyBytes`](https://doc.traefik.io/traefik/middlewares/http/buffering/#maxrequestbodybytes)\n\nThe changes themselves are deep inside Wagtail, making patching incredibly difficult.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H"
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  } ],
  "affected" : [ {
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    },
    "ranges" : [ {
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      }, {
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      } ]
    } ]
  }, {
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  "references" : [ {
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    "url" : "https://github.com/wagtail/wagtail/security/advisories/GHSA-33pv-vcgh-jfg9"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2023-28837"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wagtail/wagtail/commit/3c0c64642b9e5b8d28b111263c7f4bddad6c3880"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wagtail/wagtail/commit/c9d2fcd650a88d76ae122646142245e5927a9165"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wagtail/wagtail/commit/cfa11bbe00dbe7ce8cd4c0bbfe2a898a690df2bf"
  }, {
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    "url" : "https://github.com/wagtail/wagtail/commit/d4022310cbe497993459c3136311467c7ac6329a"
  }, {
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    "url" : "https://docs.wagtail.org/en/stable/reference/settings.html#wagtailimages-max-upload-size"
  }, {
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    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/wagtail/PYSEC-2023-56.yaml"
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  }, {
    "type" : "WEB",
    "url" : "https://github.com/wagtail/wagtail/releases/tag/v4.1.4"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/wagtail/wagtail/releases/tag/v4.2.2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400", "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-04-03T19:18:09Z",
    "nvd_published_at" : "2023-04-03T17:15:00Z"
  }
}