CVE-2020-8091: Typo3/cms Cross-Site Scripting Vulnerability

MODERATE
Advisory Identifier: GHSA-qvhv-pwww-53jj
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CVSS 6.1
CWE-79
Published
Advisory Summary

CVE-2020-8091 is a MODERATE (CVSS 6.1) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Typo3/cms libraries in the Packagist ecosystem. The issue involves typo3 cross-site scripting in flash component (elts). Remediation is available by upgrading affected packages to version 7.2.0, 6.2.39.

CVE-2020-8091 at a Glance

CVE Identifier CVE-2020-8091
GHSA Identifier GHSA-qvhv-pwww-53jj
Severity MODERATE
CVSS v3.1 Base Score 6.1
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Typo3/cms
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 6.1

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:R/S:C/C:L/I:L/A:N).

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

How to Fix CVE-2020-8091

To remediate this vulnerability, upgrade all affected Typo3/cms dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

typo3/cms fixed: 7.2.0 
Upgrade typo3/cms to 7.2.0
typo3/cms fixed: 6.2.39 
Upgrade typo3/cms to 6.2.39
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for typo3/cms

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-8091, inspect your project dependencies for Typo3/cms:

inspect dependencies for typo3/cms

Analyze the terminal output to locate any version of Typo3/cms in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.2.0), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting'), where the product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. In Typo3/cms, 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

TYPO3 6.2.0 to 6.2.38 ELTS and 7.0.0 to 7.1.0 included a vulnerable external component, which could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack on a targeted system.

CVE-2020-8091 Affected Typo3/cms Versions

2 component(s)
Fixed Versions:
7.2.06.2.39
Product / Package Ecosystem Affected Versions Fixed Version
typo3/cms
 Packagist
≥ 7.0.0
< 7.2.0
7.2.0
typo3/cms
 Packagist
≥ 6.2.0
< 6.2.39
6.2.39

References

NVD — CVE-2020-8091 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-8091
Security Fix Commit FIX COMMIT
https://github.com/TYPO3/typo3/commit/482e2e992f80f5e38cb48fcaea40fd9812a5252c
Typo3/cms Source Repository REPOSITORY
https://github.com/TYPO3/typo3
Typo3/cms Source Repository REPOSITORY
https://github.com/TYPO3/typo3/blob/4cb53e828bd5138d180cdf9cac1ccf7fd31086d2/typo3/sysext/core/Documentation/Changelog/7.2/Breaking-65962-WebSVGLibraryAndAPIRemoved.rst
Typo3/cms Security Information SECURITY
https://typo3.org/security/advisory/typo3-psa-2019-003
www.purplemet.com/blog/typo3-xss-vuln... WEB
https://www.purplemet.com/blog/typo3-xss-vulnerability

Frequently Asked Questions

What is CVE-2020-8091?
CVE-2020-8091 is a security vulnerability in Typo3/cms involving Typo3 Cross-Site Scripting in Flash component (ELTS) under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Typo3/cms versions are affected?
Affected versions include releases prior to 7.2.0, 6.2.39 across affected packages: typo3/cms.
What version fixes CVE-2020-8091?
Upgrading to 7.2.0, 6.2.39 (or the latest patched release for your respective branch) resolves the vulnerability.
Is typo3/cms affected?
Yes, typo3/cms is affected in releases prior to 7.2.0, 6.2.39. Upgrade your dependency to 7.2.0, 6.2.39 or later.
What is the CVSS score of CVE-2020-8091?
CVE-2020-8091 has a CVSS v3.1 base score of 6.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
What CWE is associated with CVE-2020-8091?
CVE-2020-8091 is classified under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') (The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users.).
How can I check Packagist dependencies for CVE-2020-8091?
Run the dependency tree command: 'inspect dependencies for typo3/cms'. 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-qvhv-pwww-53jj",
  "modified" : "2023-09-21T09:46:22Z",
  "published" : "2022-05-24T17:07:30Z",
  "aliases" : [ "CVE-2020-8091" ],
  "summary" : "Typo3 Cross-Site Scripting in Flash component (ELTS)",
  "details" : "TYPO3 6.2.0 to 6.2.38 ELTS and 7.0.0 to 7.1.0 included a vulnerable external component, which could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack on a targeted system.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.2.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 7.1.0"
    }
  }, {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "typo3/cms"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.2.0"
      }, {
        "fixed" : "6.2.39"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.2.38"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-8091"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TYPO3/typo3/commit/482e2e992f80f5e38cb48fcaea40fd9812a5252c"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/TYPO3/typo3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TYPO3/typo3/blob/4cb53e828bd5138d180cdf9cac1ccf7fd31086d2/typo3/sysext/core/Documentation/Changelog/7.2/Breaking-65962-WebSVGLibraryAndAPIRemoved.rst"
  }, {
    "type" : "WEB",
    "url" : "https://typo3.org/security/advisory/typo3-psa-2019-003"
  }, {
    "type" : "WEB",
    "url" : "https://www.purplemet.com/blog/typo3-xss-vulnerability"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-07-12T23:19:58Z",
    "nvd_published_at" : "2020-01-27T22:15:00Z"
  }
}