CVE-2020-11083: October/backend Cross-Site Scripting Vulnerability

LOW
Advisory Identifier: GHSA-w4pj-7p68-3vgv
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CVSS 3.5
CWE-79
Published
Advisory Summary

CVE-2020-11083 is a LOW (CVSS 3.5) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting October/backend libraries in the Packagist ecosystem. The issue involves stored xss in october. Remediation is available by upgrading affected packages to version 1.0.466.

CVE-2020-11083 at a Glance

CVE Identifier CVE-2020-11083
GHSA Identifier GHSA-w4pj-7p68-3vgv
Severity LOW
CVSS v3.1 Base Score 3.5
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product October/backend
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 3.5

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

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

How to Fix CVE-2020-11083

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

october/backend fixed: 1.0.466 
Upgrade october/backend to 1.0.466
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 october/backend

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-11083, inspect your project dependencies for October/backend:

inspect dependencies for october/backend

Analyze the terminal output to locate any version of October/backend in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.0.466), 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 October/backend, 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 user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field. ### Patches Issue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the `backend.allow_unsafe_markdown` permission. ### Workarounds Apply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin). ### References Reported by [Sivanesh Ashok](https://stazot.com/) ### For more information If you have any questions or comments about this advisory: * Email us at [hello@octobercms.com](mailto:hello@octobercms.com) ### Threat assessment: <img width="1100" alt="Screen Shot 2020-03-31 at 2 01 52 PM" src="https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png">

CVE-2020-11083 Affected October/backend Versions

1 component(s)
Fixed Versions:
1.0.466
Product / Package Ecosystem Affected Versions Fixed Version
october/backend
 Packagist
≥ 1.0.319
< 1.0.466
1.0.466

References

GitHub Advisory / Wiki ADVISORY
https://github.com/octobercms/october/security/advisories/GHSA-w4pj-7p68-3vgv
NVD — CVE-2020-11083 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-11083
Security Fix Commit FIX COMMIT
https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746
Security Fix Commit FIX COMMIT
https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94
October/backend Security Information SECURITY
http://packetstormsecurity.com/files/158730/October-CMS-Build-465-XSS-File-Read-File-Deletion-CSV-Injection.html
seclists.org/fulldisclosure/2020... WEB
http://seclists.org/fulldisclosure/2020/Aug/2

Frequently Asked Questions

What is CVE-2020-11083?
CVE-2020-11083 is a security vulnerability in October/backend involving Stored XSS in October under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which October/backend versions are affected?
Affected versions include releases prior to 1.0.466 across affected packages: october/backend.
What version fixes CVE-2020-11083?
Upgrading to 1.0.466 (or the latest patched release for your respective branch) resolves the vulnerability.
Is october/backend affected?
Yes, october/backend is affected in releases prior to 1.0.466. Upgrade your dependency to 1.0.466 or later.
What is the CVSS score of CVE-2020-11083?
CVE-2020-11083 has a CVSS v3.1 base score of 3.5 (LOW) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N.
What CWE is associated with CVE-2020-11083?
CVE-2020-11083 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-2020-11083?
Run the dependency tree command: 'inspect dependencies for october/backend'. 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-w4pj-7p68-3vgv",
  "modified" : "2023-01-31T01:29:13Z",
  "published" : "2020-08-05T14:52:44Z",
  "aliases" : [ "CVE-2020-11083" ],
  "summary" : "Stored XSS in October",
  "details" : "### Impact\nA user with access to a markdown FormWidget that stores data persistently could create a stored XSS attack against themselves and any other users with access to the generated HTML from the field.\n\n### Patches\nIssue has been patched in Build 466 (v1.0.466) & RainLab.Blog v1.4.1 by restricting the ability to store JS in markdown to only users that have been explicitly granted the `backend.allow_unsafe_markdown` permission.\n\n### Workarounds\nApply https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746 & https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94 to your installation manually if unable to upgrade to Build 466 or v1.4.1 of RainLab.Blog (if using that plugin).\n\n### References\nReported by [Sivanesh Ashok](https://stazot.com/)\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [hello@octobercms.com](mailto:hello@octobercms.com)\n\n### Threat assessment:\n<img width=\"1100\" alt=\"Screen Shot 2020-03-31 at 2 01 52 PM\" src=\"https://user-images.githubusercontent.com/7253840/78070158-8f7ef580-7358-11ea-950c-226533f6a0a3.png\">",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:L/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "october/backend"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.0.319"
      }, {
        "fixed" : "1.0.466"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/octobercms/october/security/advisories/GHSA-w4pj-7p68-3vgv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-11083"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/octobercms/october/commit/9ecfb4867baae14a0d3f99f5b5c1e8a979ae8746"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rainlab/blog-plugin/commit/6ae19a6e16ef3ba730692bc899851342c858bb94"
  }, {
    "type" : "WEB",
    "url" : "http://packetstormsecurity.com/files/158730/October-CMS-Build-465-XSS-File-Read-File-Deletion-CSV-Injection.html"
  }, {
    "type" : "WEB",
    "url" : "http://seclists.org/fulldisclosure/2020/Aug/2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2020-07-28T19:36:22Z",
    "nvd_published_at" : "2020-07-14T21:15:00Z"
  }
}