Vulnerabilities in pkg:pypi/plone.supermodel

PACKAGE
Advisory Identifier: GHSA-wq6x-g685-w5f2
Advisory Summary

CVE-2020-28734 is a HIGH (CVSS 8.8) improper restriction of xml external vulnerability (CWE-611: Improper Restriction of XML External Entity Reference) affecting Plone libraries in the PyPI ecosystem. The issue involves improper restriction of xml external entity reference in plone. Remediation is available by upgrading affected packages to version 5.2.3, 3.2.10, 4.1.6, 2.6.8, 1.6.3.

3 Known Advisory Record(s)
Package Vulnerability Intelligence

pkg:pypi/plone.supermodel

3 Known Advisory Record(s)

Vulnerability advisories affecting package pkg:pypi/plone.supermodel. Select an advisory below to view technical details or fixes.

Advisory ID CVE / NVD Severity Summary
GHSA-wq6x-g685-w5f2 CVE-2020-28734 HIGH Improper Restriction of XML External Entity Reference in Plone
GHSA-x7wf-5mjc-6x76 CVE-2020-28735 HIGH SSRF attacks via tracebacks in Plone
GHSA-2c8c-84w2-j38j CVE-2020-28736 HIGH Improper Restriction of XML External Entity Reference in Plone

CVE-2020-28734 at a Glance

CVE Identifier CVE-2020-28734
GHSA Identifier GHSA-wq6x-g685-w5f2
Severity HIGH
CVSS v3.1 Base Score 8.8
CWE Classification CWE-611: Improper Restriction of XML External Entity Reference
Affected Product Plone
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 8.8

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

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

How to Fix CVE-2020-28734

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

Plone fixed: 5.2.3
pip install Plone>=5.2.3
plone.app.event fixed: 3.2.10
pip install plone.app.event>=3.2.10
plone.app.theming fixed: 4.1.6
pip install plone.app.theming>=4.1.6
plone.app.dexterity fixed: 2.6.8
pip install plone.app.dexterity>=2.6.8
plone.supermodel fixed: 1.6.3
pip install plone.supermodel>=1.6.3
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 Plone

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2020-28734, inspect your installed packages using pip:

pip show Plone

Analyze the terminal output to locate any version of Plone in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.2.3), your application is affected.

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

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-611: Improper Restriction of XML External Entity Reference, where the product processes an xml document that can contain xml entities with uris that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output. In Plone, 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

Plone before 5.2.3 allows XXE attacks via a feature that is explicitly only available to the Manager role.

CVE-2020-28734 Affected Plone Versions

5 component(s)
Fixed Versions:
5.2.33.2.104.1.62.6.81.6.3
Product / Package Ecosystem Affected Versions Fixed Version
Plone
PyPI
< 5.2.3
5.2.3
plone.app.event
PyPI
< 3.2.10
3.2.10
plone.app.theming
PyPI
< 4.1.6
4.1.6
plone.app.dexterity
PyPI
< 2.6.8
2.6.8
plone.supermodel
PyPI
< 1.6.3
1.6.3

References

Frequently Asked Questions

What is CVE-2020-28734?
CVE-2020-28734 is a security vulnerability in Plone involving Improper Restriction of XML External Entity Reference in Plone under CWE-611: Improper Restriction of XML External Entity Reference.
Which Plone versions are affected?
Affected versions include releases prior to 5.2.3, 3.2.10, 4.1.6, 2.6.8, 1.6.3 across affected packages: Plone, plone.app.event, plone.app.theming, plone.app.dexterity, plone.supermodel.
What version fixes CVE-2020-28734?
Upgrading to 5.2.3, 3.2.10, 4.1.6, 2.6.8, 1.6.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Plone affected?
Yes, Plone is affected in releases prior to 5.2.3. Upgrade your dependency to 5.2.3 or later.
Is plone.app.event affected?
Yes, plone.app.event is affected in releases prior to 3.2.10. Upgrade your dependency to 3.2.10 or later.
What is the CVSS score of CVE-2020-28734?
CVE-2020-28734 has a CVSS v3.1 base score of 8.8 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2020-28734?
CVE-2020-28734 is classified under CWE-611: Improper Restriction of XML External Entity Reference (The product processes an XML document that can contain XML entities with URIs that resolve to documents outside of the intended sphere of control, causing the product to embed incorrect documents into its output.).
How can I check PyPI dependencies for CVE-2020-28734?
Run the dependency tree command: 'pip show Plone'. 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-wq6x-g685-w5f2",
  "modified" : "2024-10-17T20:59:18Z",
  "published" : "2021-04-07T21:13:00Z",
  "aliases" : [ "CVE-2020-28734" ],
  "summary" : "Improper Restriction of XML External Entity Reference in Plone",
  "details" : "Plone before 5.2.3 allows XXE attacks via a feature that is explicitly only available to the Manager role.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "Plone"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "5.2.3"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "plone.app.event"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.2.10"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "plone.app.theming"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "4.1.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "plone.app.dexterity"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.6.8"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "plone.supermodel"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.6.3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-28734"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/plone/Products.CMFPlone/issues/3209"
  }, {
    "type" : "WEB",
    "url" : "https://dist.plone.org/release/5.2.3/RELEASE-NOTES.txt"
  }, {
    "type" : "ADVISORY",
    "url" : "https://github.com/advisories/GHSA-wq6x-g685-w5f2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/plone/PYSEC-2020-246.yaml"
  }, {
    "type" : "WEB",
    "url" : "https://www.misakikata.com/codes/plone/python-en.html"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-611" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-04-07T19:34:40Z",
    "nvd_published_at" : "2020-12-30T19:15:00Z"
  }
}