pysec - pysec-2020-231

PYSEC-2020-231

Vulnerability from pysec - Published: 2020-01-28 23:15 - Updated: 2021-08-27 03:22

Details

Feedgen (python feedgen) before 0.9.0 is susceptible to XML Denial of Service attacks. The feedgen library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to XML Denial of Service Attacks (e.g. XML Bomb). This becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only. This problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.

Impacted products

Name	purl
feedgen	pkg:pypi/feedgen

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "feedgen",
        "purl": "pkg:pypi/feedgen"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "f57a01b20fa4aaaeccfa417f28e66b4084b9d0cf"
            }
          ],
          "repo": "https://github.com/lkiesow/python-feedgen",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1",
        "0.2",
        "0.2.1",
        "0.2.2",
        "0.2.2.1",
        "0.2.3",
        "0.2.4",
        "0.2.5",
        "0.2.6",
        "0.2.7",
        "0.2.8",
        "0.3.0",
        "0.3.1",
        "0.3.2",
        "0.4.0",
        "0.4.1",
        "0.5.0",
        "0.5.1",
        "0.6.0",
        "0.6.1",
        "0.7.0",
        "0.8.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2020-5227",
    "GHSA-g8q7-xv52-hf9f"
  ],
  "details": "Feedgen (python feedgen) before 0.9.0 is susceptible to XML Denial of Service attacks. The *feedgen* library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to XML Denial of Service Attacks (e.g. XML Bomb). This becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only. This problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.",
  "id": "PYSEC-2020-231",
  "modified": "2021-08-27T03:22:03.690780Z",
  "published": "2020-01-28T23:15:00Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/lkiesow/python-feedgen/security/advisories/GHSA-g8q7-xv52-hf9f"
    },
    {
      "type": "WEB",
      "url": "https://docs.microsoft.com/en-us/archive/msdn-magazine/2009/november/xml-denial-of-service-attacks-and-defenses"
    },
    {
      "type": "FIX",
      "url": "https://github.com/lkiesow/python-feedgen/commit/f57a01b20fa4aaaeccfa417f28e66b4084b9d0cf"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T6I5ENUYGFNMIH6ZQ62FZ6VU2WD3SIOI/"
    }
  ]
}

CVE-2020-5227 (GCVE-0-2020-5227)

Vulnerability from cvelistv5 – Published: 2020-01-28 22:40 – Updated: 2024-08-04 08:22

Summary

Feedgen (python feedgen) before 0.9.0 is susceptible to XML Denial of Service attacks. The *feedgen* library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to XML Denial of Service Attacks (e.g. XML Bomb). This becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only. This problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.

Severity ?

4.4 (Medium)


                        
                          CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

CWE

CWE-776 - Improper Restriction of Recursive Entity References in DTDs ('XML Entity Expansion')

Assigner

GitHub_M

References

URL

Tags

	https://github.com/lkiesow/python-feedgen/securit…	x_refsource_CONFIRM
	https://docs.microsoft.com/en-us/archive/msdn-mag…	x_refsource_MISC
	https://github.com/lkiesow/python-feedgen/commit/…	x_refsource_MISC
	https://lists.fedoraproject.org/archives/list/pac…	vendor-advisoryx_refsource_FEDORA

Impacted products

	Vendor	Product	Version
	lkiesow	python-feedgen	Affected: < 0.9.0

Show details on NVD website

JSON

To clipboard

{
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GHSA-G8Q7-XV52-HF9F

Vulnerability from github – Published: 2020-01-28 22:37 – Updated: 2024-09-20 17:44

Summary

Feedgen Vulnerable to XML Denial of Service Attacks

Details

Impact

The feedgen library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to XML Denial of Service Attacks (e.g. XML Bomb).

This becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only.

Patches

This problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.

Workarounds

Updating is strongly recommended and should not be problematic. Nevertheless, as a workaround, avoid providing XML directly to feedgen or ensure that no entity expansion is part of the XML.

References

For more information

If you have any questions or comments about this advisory: - Open an issue in lkiesow/python-feedgen - Send an email to security@lkiesow.de

Severity ?

4.4 (Medium)


                  
                    CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H

5.9 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "feedgen"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2020-5227"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-776"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2020-01-28T22:34:51Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nThe *feedgen* library allows supplying XML as content for some of the available fields. This XML will be parsed and integrated into the existing XML tree. During this process, feedgen is vulnerable to [XML Denial of Service Attacks](https://docs.microsoft.com/en-us/archive/msdn-magazine/2009/november/xml-denial-of-service-attacks-and-defenses) (e.g. XML Bomb).\n\nThis becomes a concern in particular if feedgen is used to include content from untrused sources and if XML (including XHTML) is directly included instead of providing plain tex content only.\n\n### Patches\n\nThis problem has been fixed in feedgen 0.9.0 which disallows XML entity expansion and external resources.\n\n### Workarounds\n\nUpdating is strongly recommended and should not be problematic. Nevertheless, as a workaround, avoid providing XML directly to feedgen or ensure that no entity expansion is part of the XML. \n\n### References\n\n- [Security Briefs - XML Denial of Service Attacks and Defenses](https://docs.microsoft.com/en-us/archive/msdn-magazine/2009/november/xml-denial-of-service-attacks-and-defenses)\n- [Billion laughs attack](https://en.wikipedia.org/wiki/Billion_laughs_attack#cite_note-2)\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n- Open an issue in [lkiesow/python-feedgen](https://github.com/lkiesow/python-feedgen/issues)\n- Send an email to security@lkiesow.de",
  "id": "GHSA-g8q7-xv52-hf9f",
  "modified": "2024-09-20T17:44:21Z",
  "published": "2020-01-28T22:37:50Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/lkiesow/python-feedgen/security/advisories/GHSA-g8q7-xv52-hf9f"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2020-5227"
    },
    {
      "type": "WEB",
      "url": "https://github.com/lkiesow/python-feedgen/commit/f57a01b20fa4aaaeccfa417f28e66b4084b9d0cf"
    },
    {
      "type": "WEB",
      "url": "https://docs.microsoft.com/en-us/archive/msdn-magazine/2009/november/xml-denial-of-service-attacks-and-defenses"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/lkiesow/python-feedgen"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/feedgen/PYSEC-2020-231.yaml"
    },
    {
      "type": "WEB",
      "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/T6I5ENUYGFNMIH6ZQ62FZ6VU2WD3SIOI"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Feedgen Vulnerable to XML Denial of Service Attacks"
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

PYSEC-2020-231

CVE-2020-5227 (GCVE-0-2020-5227)

GHSA-G8Q7-XV52-HF9F

Impact

Patches

Workarounds

References

For more information

Tags

Sightings

Nomenclature