CVE-2020-26211: Ssddanbrown/bookstack Cross-Site Scripting Vulnerability

HIGH
Advisory Identifier: GHSA-ch37-ch8w-cfrq
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CVSS 8.7
CWE-79
Published
Advisory Summary

CVE-2020-26211 is a HIGH (CVSS 8.7) cross-site scripting vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')) affecting Ssddanbrown/bookstack libraries in the Packagist ecosystem. The issue involves bookstack cross-site scripting vulnerability. Remediation is available by upgrading affected packages to version 0.30.4.

CVE-2020-26211 at a Glance

CVE Identifier CVE-2020-26211
GHSA Identifier GHSA-ch37-ch8w-cfrq
Severity HIGH
CVSS v3.1 Base Score 8.7
CWE Classification CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Affected Product Ssddanbrown/bookstack
Package Ecosystem Packagist
Published Date
Last Updated

Security Impact

CVSS: 8.7

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

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

How to Fix CVE-2020-26211

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

ssddanbrown/bookstack fixed: 0.30.4 
Upgrade ssddanbrown/bookstack to 0.30.4
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 ssddanbrown/bookstack

How to Check if You Are Affected

To determine whether your application is affected by CVE-2020-26211, inspect your project dependencies for Ssddanbrown/bookstack:

inspect dependencies for ssddanbrown/bookstack

Analyze the terminal output to locate any version of Ssddanbrown/bookstack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.30.4), 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 Ssddanbrown/bookstack, 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

In BookStack before version 0.30.4, a user with permissions to edit a page could insert JavaScript code through the use of `javascript:` URIs within a link or form which would run, within the context of the current page, when clicked or submitted. Additionally, a user with permissions to edit a page could insert a particular meta tag which could be used to silently redirect users to a alternative location upon visit of a page. Dangerous content may remain in the database but will be removed before being displayed on a page. If you think this could have been exploited the linked advisory provides a SQL query to test. As a workaround without upgrading, page edit permissions could be limited to only those that are trusted until you can upgrade although this will not address existing exploitation of this vulnerability. The issue is fixed in BookStack version 0.30.4.

CVE-2020-26211 Affected Ssddanbrown/bookstack Versions

1 component(s)
Fixed Versions:
0.30.4
Product / Package Ecosystem Affected Versions Fixed Version
ssddanbrown/bookstack
 Packagist
< 0.30.4
0.30.4

References

GitHub Advisory / Wiki ADVISORY
https://github.com/BookStackApp/BookStack/security/advisories/GHSA-r2cf-8778-3jgp
NVD — CVE-2020-26211 NVD
https://nvd.nist.gov/vuln/detail/CVE-2020-26211
Security Fix Commit FIX COMMIT
https://github.com/BookStackApp/BookStack/commit/bbd1384acbe7e52c21f89af69f2dc391c95dbf54
Ssddanbrown/bookstack Source Repository REPOSITORY
https://github.com/BookStackApp/BookStack
Ssddanbrown/bookstack Release RELEASE
https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4
www.bookstackapp.com/blog/beta-release-v... WEB
https://www.bookstackapp.com/blog/beta-release-v0-30-4

Frequently Asked Questions

What is CVE-2020-26211?
CVE-2020-26211 is a security vulnerability in Ssddanbrown/bookstack involving Bookstack Cross-site Scripting vulnerability under CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').
Which Ssddanbrown/bookstack versions are affected?
Affected versions include releases prior to 0.30.4 across affected packages: ssddanbrown/bookstack.
What version fixes CVE-2020-26211?
Upgrading to 0.30.4 (or the latest patched release for your respective branch) resolves the vulnerability.
Is ssddanbrown/bookstack affected?
Yes, ssddanbrown/bookstack is affected in releases prior to 0.30.4. Upgrade your dependency to 0.30.4 or later.
What is the CVSS score of CVE-2020-26211?
CVE-2020-26211 has a CVSS v3.1 base score of 8.7 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N.
What CWE is associated with CVE-2020-26211?
CVE-2020-26211 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-2020-26211?
Run the dependency tree command: 'inspect dependencies for ssddanbrown/bookstack'. 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-ch37-ch8w-cfrq",
  "modified" : "2023-07-20T14:49:19Z",
  "published" : "2022-05-24T17:32:59Z",
  "aliases" : [ "CVE-2020-26211" ],
  "summary" : "Bookstack Cross-site Scripting vulnerability",
  "details" : "In BookStack before version 0.30.4, a user with permissions to edit a page could insert JavaScript code through the use of `javascript:` URIs within a link or form which would run, within the context of the current page, when clicked or submitted. Additionally, a user with permissions to edit a page could insert a particular meta tag which could be used to silently redirect users to a alternative location upon visit of a page. Dangerous content may remain in the database but will be removed before being displayed on a page. If you think this could have been exploited the linked advisory provides a SQL query to test. As a workaround without upgrading, page edit permissions could be limited to only those that are trusted until you can upgrade although this will not address existing exploitation of this vulnerability. The issue is fixed in BookStack version 0.30.4.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Packagist",
      "name" : "ssddanbrown/bookstack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.30.4"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/BookStackApp/BookStack/security/advisories/GHSA-r2cf-8778-3jgp"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2020-26211"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/BookStackApp/BookStack/commit/bbd1384acbe7e52c21f89af69f2dc391c95dbf54"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/BookStackApp/BookStack"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/BookStackApp/BookStack/releases/tag/v0.30.4"
  }, {
    "type" : "WEB",
    "url" : "https://www.bookstackapp.com/blog/beta-release-v0-30-4"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-79" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-07-20T14:49:19Z",
    "nvd_published_at" : "2020-11-03T21:15:00Z"
  }
}